appendix e - transport for nsw

Appendix ERoads and Maritime
M1 Pacific Motorway, Kariong Ramps and M1 Kariong to Somersby Widening
Traffic and Transport Assessment Report
14 October 2014
Roads and Maritime M1 Pacific Motorway, Kariong Ramps and M1 Kariong to Somersby Widening - Traffic and Transport Assessment Report
Contents
2.1 Corridor description 5
2.3 Freight routes 6
2.4 Land use 8
2.5 Public transport 9
3. Traffic volumes and patterns 11
3.1 Traffic surveys 11
3.3 Intersection counts and queue length surveys 12
3.4 Traffic results 13
4. Traffic modelling process 25
4.1 Previous modelling 25
4.3 Modelling assumptions 25
4.4 Review comments 28
4.6 Traffic performance criteria 29
5. Existing modelled network performance 31
5.1 M1 Pacific Motorway 31
5.2 Central Coast Highway 33
5.3 Discussion 34
Parsons Brinckerhoff | 2113226A-TR-PR-001 RevD i
Contents (Continued)
Page number
6.1 Future network assumptions 36
6.2 M1 Pacific Motorway 36
6.3 Central Coast Highway 39
6.4 Network statistics 40
6.6 Sensitivity 47
7.2 Crash history 51
7.4 Crash savings 53
7.6 Key findings 56
8.1 Public transport 59
8.3 Freight transport 59
8.5 Operational impacts 59
8.6 Management of impacts 60
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List of tables
Page number
Table 3.1 Average weekday daily and peak hour traffic volumes 13 Table 3.2 Average daily weekday and weekend traffic volumes on key roads 14 Table 3.3 Total vehicles and heavy vehicles per day in study area 21 Table 3.4 Year 2039 freeway AM peak volumes 22 Table 3.5 Year 2039 Kariong interchange AM peak volumes 22 Table 3.6 Year 2039 freeway PM peak volumes 22 Table 3.7 Year 2039 Kariong interchange PM peak volumes 23 Table 4.1 Population and employment growth within catchment area 27 Table 4.2 Forecast AADT on M1 Pacific Motorway between Kariong and Somersby 28 Table 4.3 Level of Service criteria for main carriageways 29 Table 4.4 Level of Service criteria for merges and diverges 29 Table 4.5 Level of Service criteria for intersections 30 Table 5.1 AM travel times 2013 Base 31 Table 5.2 PM travel times 2013 Base 31 Table 5.3 AM freeway performance 2013 Base 32 Table 5.4 AM Kariong interchange ramp performance 2013 Base 32 Table 5.5 PM freeway performance 2013 Base 32 Table 5.6 PM Kariong interchange ramp performance 2013 Base 33 Table 5.7 AM intersection performance 2013 Base 33 Table 5.8 PM intersection performance 2013 Base 33 Table 6.1 AM travel times 2039 36 Table 6.2 PM travel times 2039 36 Table 6.3 AM Freeway performance 2039 37 Table 6.4 AM Kariong interchange ramp performance 2039 37 Table 6.5 PM freeway performance 2039 38 Table 6.6 PM Kariong interchange ramp performance 2039 38 Table 6.7 AM intersection performance 2039 39 Table 6.8 PM Intersection performance 2039 39 Table 6.9 Network statistics 40 Table 6.10 AM travel times 2039 sensitivity 47 Table 6.11 PM travel times 2039 sensitivity 47 Table 6.12 AM freeway performance 2039 sensitivity 48 Table 6.13 AM Kariong interchange ramp performance 2039 sensitivity 48 Table 6.14 PM freeway performance 2039 sensitivity 48 Table 6.15 PM Kariong interchange ramp performance 2039 sensitivity 49 Table 6.16 AM intersection performance 2039 sensitivity 49 Table 6.17 PM intersection performance 2039 sensitivity 49 Table 7.1 Summary of crash data (October 2007 to September 2012) 52 Table 7.2 Existing crash rate on the subject section of the M1 Pacific Motorway 53 Table 7.3 Impact on road safety 54 Table 7.4 Predicted crash rates on the Pacific Motorway 56
Parsons Brinckerhoff | 2113226A-TR-PR-001 RevD iii
List of figures
Page number
Figure 1.1 Road network and modelling study area 2 Figure 2.1 Posted speed limits in the study area 6 Figure 2.2 Designated B-double routes in the study area 7 Figure 2.3 Existing land use in the study area 8 Figure 2.4 Bus routes servicing the study area 9 Figure 2.5 Existing cycle routes in the study area 10 Figure 3.1 Location of survey data collected for the study 12 Figure 3.2 Average weekly two-way traffic volumes on key roads 15 Figure 3.3 Daily traffic profiles for key roads 17 Figure 3.4 Seasonal variation of traffic on M1 Pacific Motorway at Reeves Road overpass 18 Figure 3.5 Existing morning peak hour turning volumes 19 Figure 3.6 Existing afternoon peak hour turning volumes 20 Figure 4.1 Projected AADT growth on M1 Pacific Motorway between Kariong and Somersby 26 Figure 4.2 Catchment area of M1 section between Somersby and Kariong (2031 AM peak
model) 27 Figure 6.1 Proposed upgrades in option 2B 35 Figure 6.2 Queues from the Kariong interchange southbound entry ramp merge to the Central
Coast Highway 41 Figure 6.3 Queues on the northbound exit ramp at the Kariong Interchange 42 Figure 6.4 Performance of the southbound entry ramp AM 2039 43 Figure 6.5 Performance of the northbound entry ramp PM2039 45 Figure 6.6 Performance of the northbound exit ramp with 500 m exit lane 46 Figure 6.7 Performance of the northbound two lane exit ramp 47 Figure 7.1 Crash movements on the Pacific Motorway between Kariong and Somersby
interchanges 53
Appendix C Wiseman Ferry Road/Central Coast Highway SIDRA analysis
iv Parsons Brinckerhoff | 2113226A-TR-PR-001 RevD
1. Introduction
Roads and Maritime proposes to widen the Pacific Motorway to six lanes between the Kariong and
Somersby interchanges. Parsons Brinckerhoff was commissioned by Roads and Maritime to undertake a
traffic and transport impact assessment of the project options. Paramics micro simulation software was used
to assess the traffic impacts. The modelling provides detailed input into the design and environmental
assessment process to help quantify the benefits of the proposed upgrade options.
1.1 Project background
The Pacific Motorway (M1), formerly known as the F3 Freeway, is part of the National Land Transport
Network (NLTN) servicing the Sydney-Brisbane Corridor for more than 75,000 cars and 7,000 heavy vehicles
between Sydney and the Central Coast. Approximately 40,000 vehicles per day travel through the Kariong
Interchange, utilising the Kariong entry and exit ramps. The Central Coast region is a major origin and
destination for road-based transport to access Gosford City, Wyong Shire, and the Kariong/Somersby
industrial areas given relatively high levels of car ownership and demand to commute to Sydney/Newcastle
to access employment opportunities.
The Motorway between Central Coast Highway (Kariong Interchange) and Peats Ridge Road (Somersby
Interchange) provides for both long distance through traffic and local traffic from north of Gosford accessing
the Central Coast.
At present traffic operation at the Kariong interchange is gradually deteriorating as traffic demand exceeds
the available capacity causing reduced speeds, queuing and delays. Further, inadequate ramp and merge
lane lengths restrict vehicles, and in particular heavy vehicles, from reaching motorway speeds when
entering the motorway, causing turbulence in the vicinity of the merge and increasing the risk of crashes.
These operational problems would be exacerbated over time by:
increases in population and employment growth in the Central Coast and
growth in local freight traffic and on the M1 main carriageways
The project is twofold and involves:
upgrading of three of the four ramps at Central Coast Highway Kariong Interchange, including widening
and lengthening as required and
generally, to widen the Pacific Motorway to six lanes between Central Coast Highway and Peats Ridge
Road to provide a six-lane, median divided carriageway to Class M (motorway) standard with grade
separated interchanges.
A strategic traffic and transportation study was previously undertaken by Hyder Consulting and the outcomes
contained in a report for Roads and Maritime Services – ‘M1 Pacific Motorway Widening between the
Kariong and Somersby Interchanges, Traffic Modelling Report (Volume 1)’ dated December 2013. Hyder
Consulting’s report is frequently referenced throughout this report.
The next stage of the project is to undertake concept design and environmental assessment. This
assessment is part of that task.
Parsons Brinckerhoff | 2113226A-TR-PR-001 RevD 1
1.2 Study area
The project study area generally covers the main carriageways of the M1 Pacific Motorway from Central
Coast Highway - the Kariong interchange, to Peats Ridge Road - the Somersby interchange. The Kariong
interchange encompasses the northerly oriented ramps at Wisemans Ferry Road and the Central Coast
Highway/Wisemans Ferry Road intersection.
1.3 Study objectives
The purpose of this traffic and transport assessment is to:
review the existing traffic and transportation study report and modelling undertaken during the strategic
stage of investigation and verify strategic design and concept design assumptions.
detail and model potential impacts of the project during construction in the short term and operation
under the design year volumes
undertake and report upon a traffic and transport assessment of the project.
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1.4 Report structure
The report has the following eight sections:
Section 1: Introduction. Describes the background of the M1 upgrade, objectives and activities of this
traffic assessment
Section 2: Existing conditions. Describes the existing road network and traffic conditions in the AM and
PM peak hours
Section 3: Traffic volumes and patterns. Describes the existing and expected traffic
Section 4: Traffic modelling. Describes the modelling process, assumptions and calibration
Section 5: Existing road network. Describes the modelled performance of the existing road network
under the existing traffic
Section 6: Future Network performance. Presents the micro simulation modelling results of both the do
nothing case and options to improve/optimise operation under design year traffic
Section 7: Road safety assessment. Presents an assessment of a crash data analysis and describes
impacts on road safety, pedestrians and cyclists
Section 8: Summary. Summarises the findings in relation to the traffic impact and road safety
assessment of the proposed M1 intersection upgrade.
2. Existing traffic and transport conditions
The existing traffic and transport conditions described in the report by Hyder Consulting referred to in section
1.1 above have been reviewed. Hyder Consulting’s reporting is considered to be a fair and reasonable
representation of the existing conditions and is replicated in this section.
2.1 Corridor description
The M1 Pacific Motorway is a critical link in the National Land Transport Network and is part of the Sydney to
Brisbane corridor, which is one of the busiest transport corridors in Australia. The link provides a vital
connection from Sydney to the Central Coast, Newcastle and Hunter regions of New South Wales. It also
links with the New England and Pacific Highways connecting northern NSW regional centres and
Queensland.
The 8 kilometre section of motorway between the Kariong and Somersby interchanges is currently two lanes
in each direction with the exception of a 3 km long segment in the northbound carriageway extending from
the Kariong Interchange. Central Coast Highway is the major road link between the M1 Pacific Motorway and
Gosford, Erina and surrounding Coastal suburbs. RMS recently upgraded the Wisemans Ferry Road/Central
Coast Highway intersection and the intersection of the northbound entry ramp with Wisemans Ferry Road.
2.2 Road hierarchy and speed environment
Pacific Motorway
The Pacific Motorway is classified as a national freeway as part of the AusLink National Network and under
the development and maintenance responsibility of NSW Roads and Maritime. The existing Pacific Motorway
within the study area provides a high standard alignment with a four lane divided road configuration and high
speed driving conditions with a posted speed limit of 110 km/h. Access onto the motorway in the study area
is via two interchanges at Kariong and Somersby.
Central Coast Highway
Central Coast Highway is classified as a highway (HW30), linking the Pacific Highway at its intersection with
Wisemans Ferry Road , just west of the motorway, with the township of Gosford and the coast to the east. It
is a four-lane divided road with a posted speed limit of 70 km/h between the motorway and the outskirts of
Gosford.
The posted speed limit on M1 Pacific Motorway is 110 km/h. A 70 km/h posted speed limit applies to Central
Coast Highway. The posted speed limits in the study area are shown in Figure 2.1 below.
Figure 2.1 Posted speed limits in the study area
2.3 Freight routes
Transport for NSW has defined the following road sections as freight routes located within the study area:
Pacific Motorway – Primary freight route which serves the needs of freight for access interstate and to
strategically important ports, airports, industrial areas, freight terminals and hubs within the Sydney,
Newcastle and Wollongong area. This route typically carries high volumes of heavy freight vehicles
(>4000 heavy vehicle AADT) and concentrations of road freight including high concentrations of live-
haul, long distance and high capacity trucks. The northbound rising grade through the Kariong
interchange is in the vicinity of 6%. This restricts heavy vehicles to a crawl speed of around 30 km/h and
these vehicles predominate in the left hand lane.
Central Coast Highway – Tertiary freight route which provides connection from the state road system to
the primary freight routes. These routes serve the numerous major businesses and freight origins and
destinations within a subregion and carry less than 2,000 heavy vehicles per day.
Both of these routes are designated B-double truck routes and accommodate vehicles with a maximum
vertical height clearance of 4.6 m. Figure 2.2 below shows designated B-double routes in the study area
sourced from RMS. Other key local roads in the study area include Wisemans Ferry Road, Pacific Highway,
Woy Woy Road and Peats Ridge Road.
Source: http://www.rms.nsw.gov.au/heavyvehicles/ravmap/
Source: Transport for NSW, Metropolitan Road Freight Hierarchy on the State Road Network Practise Note
Figure 2.2 Designated B-double routes in the study area
2.4 Land use
The Pacific Motorway in the study area is generally oriented north to south. The predominant existing land
uses in proximity to the Pacific Motorway include:
general industrial development to the north of the Kariong interchange and west of the motorway
the area north of the industrial estate and abutting the Pacific Motorway is mostly zoned for either
primary production or as rural landscape
an area south and east of the Somersby interchange where a decision on the land use has been
deferred.
The existing land use is shown in Figure 2.3 below.
Source: http://gems1.gosford.nsw.gov.au/zoning/
2.5 Public transport
The study area is serviced by two routes all operated by Busways. Figure 2.4 shows the bus routes in the
study area. The Gosford Railway Station is more than 5 km away from the Kariong interchange and is
serviced by the Newcastle and Central Coast Line.
Source: http://www.busways.com.au/sites/default/files/network_maps/R6NetworkGosford.pdf
2.6 Walking and cycling
Pedestrians are not allowed on the M1 Pacific Motorway. Dedicated footpaths are provided along the Central
Coast Highway. Cycling is allowed on the roads shoulders on M1 Pacific Motorway, north of Kariong
interchange but cycling is not allowed south of the interchange. Dedicated cycle ways are provided on
Central Coast Highway as shown in Figure 2.5.
Source: http://www.bicycleinfo.nsw.gov.au/maps/cycleway_finder.html
3. Traffic volumes and patterns The results of Hyder Consulting’s investigation into the existing network performance as described in the
report by Hyder Consulting referred to in section 1.1 above have been reviewed. Hyder Consulting’s
reporting is considered to be a fair and reasonable representation of the existing network performance and is
replicated in this section.
Details of the traffic counts and surveys referenced below are also appended to the Hyder Consulting report.
3.1 Traffic surveys
To satisfy the modelling requirements, RMS undertook an extensive data collection exercise involving key
roads and intersections in the study area. Traffic surveys were undertaken as an input into the micro
simulation (Paramics) model calibration and validation.
Three types of survey were undertaken to satisfy the needs and purpose of the study. They were:
intersection turning movement counts for the critical peak periods
daily automatic traffic counts on midblock locations for a one week period
queue length surveys at critical intersections.
3.2 Midblock traffic counts
Midblock traffic counts were collected by RMS in May and September 2013 at various locations in the study
area. RMS provided classified midblock counts for the following locations in or adjacent to the study area
(refer also to Figure 3.1 below):
Wisemans Ferry Road northbound entry ramp ( Kariong Interchange)
Wisemans Ferry Road southbound exit ramp (Kariong Interchange)
Peats Ridge Road northbound Entry ramp (Somersby Interchange)
Peats Ridge Road northbound exit ramp (Somersby Interchange)
Peats Ridge Road southbound entry ramp (Somersby Interchange)
Peats Ridge Road southbound exit ramp (Somersby Interchange)
Central Coast Highway – south of Wisemans Ferry Road.
Daily hourly volumes (unclassified) on M1 motorway were also collected at the RMS permanent count station
at Reeves Road Overpass.
3.3 Intersection counts and queue length surveys
The intersection turning movements and queue length data was collected by RMS in May and September
2013. RMS undertook intersection count and queue length surveys for the AM peak (5.00 am to 9.00 am)
and the PM peak (3.00 pm to 7.00 pm) for the following five study intersections:
Central Coast Highway/Pacific Highway roundabout
Central Coast Highway/Wisemans Ferry Road
Central Coast Highway/Kangoo Road
Central Coast Highway/Curringa Road
Central Coast Highway/Woy Woy Road.
Figure 3.1 below shows the location of intersection counts and the midblock counts collected for the study.
Source: M1 Pacific Motorway Widening Between the Kariong and Somersby Interchanges, Traffic Modelling Report (Volume 1) Hyder Consulting dated December 2013
Figure 3.1 Location of survey data collected for the study
3.4 Traffic results
3.4.1 Intersection traffic profile
The intersection turning movement data was used to assess existing capacity problems at key intersections
on the Central Coast Highway. The traffic data also provides a basis to consider likely traffic changes that
would result from future growth. The results are based on survey data recorded from key roads and
intersections in 2013.
Table 3.1 below summarises the average daily, morning and afternoon peak hour traffic volumes at key
roads in the study area. The peak period occurs between 6.00 am and 8.00 am in the morning and between
3.00 pm and 5.00 pm in the evening. The data in Table 3.1 shows that:
Central Coast Highway carried about daily 41,300 vehicles between Kangoo Road and M1 Pacific
Motorway Ramps. During the peak hour, Central Coast Highway carried between 3,300 and
3,500 vehicles.
Daily traffic on the northbound entry ramp with Wisemans Ferry Road was 6,200 vehicles slightly lower
than southbound exit ramp which was 6,400 vehicles. During peak hour either ramp carried between
430 and 690 vehicles.
Daily traffic on Peats Ridge Road is low in the order of 500 to 1,100 vehicles per day. In one peak hour
ramps carried between 30 and 130 vehicles. During AM peak hour southbound entry/exit ramps carried
relatively more traffic than northbound entry/exist ramps.
Wisemans Ferry Road northbound entry ramp carried about 430 and 690 vehicles in one hour in AM
and PM peak periods respectively.
Wisemans Ferry Road southbound exit ramp carried about 500 and 600 vehicles in one hour in AM and
PM peak periods respectively.
Table 3.1 Average weekday daily and peak hour traffic volumes
Note: Northbound (NB), Eastbound (EB), Southbound (SB), Westbound (WB)
3.4.2 Weekly traffic profile
Table 3.2 shows the average daily traffic volumes in the study area for weekday and weekend. Average
weekly two-way traffic volume profiles are shown in M1 Pacific Motorway Widening Between the Kariong and
Somersby Interchanges, Traffic Modelling Report (Volume 1) Hyder Consulting dated December 2013.
The results in Table 3.2 indicate that:
The average weekday and weekend traffic on M1 Pacific Motorway are similar with weekend traffic only
3% lower than the weekday traffic.
Average weekend traffic is approximately 19% lower than weekday traffic on the Central Coast
Highway.
Average weekend traffic is approximately between 36% and 37% lower than weekday traffic on the
Wisemans Ferry Road entry and exit ramps.
Average weekend traffic is approximately between 8% and 14% lower than weekday traffic at entry and
exit ramps at Somersby interchange.
Table 3.2 Average daily weekday and weekend traffic volumes on key roads
Figure 3.2 Average weekly two-way traffic volumes on key roads
3.4.3 Daily traffic profile
Daily traffic volume profiles for all five surveyed sites are shown in Figure 3.3. The profiles for all sites
suggest the morning and evening peak hour durations as follows:
morning peak between 6.00 and 8.00 am
afternoon peak between 3.00 and 5.00 pm.
The morning peak spreads over two hours between 06.00 am and 08.00 am, with traffic building up sharply
between 7.00 am and 8.00 am. The hour between 6.00 am and 7.00 am shows the predominant peak. The
afternoon peak also spreads over two hours between 3.00 pm and 5.00 pm, with traffic building up sharply
after 3:00 pm. The predominant peak is reached around 4.00 pm and starts to decline sharply after 5.00 pm.
On the M1 Pacific Motorway the afternoon peak hour traffic is about 19% higher than the morning peak hour
traffic.
Figure 3.3 Daily traffic profiles for key roads
3.4.4 Seasonal variations
To determine the seasonal variation of traffic, historical data was sourced from RMS permanent count station
on M1 Pacific Motorway at Reeves Road overpass. The historical data represents daily traffic from June
2012 to June 2013. Figure 3.4 shows the monthly variation in traffic for the period from June 2012 to June
2013. The graph indicates that monthly traffic volumes increased from October to December and then
decreased from January to March. From the graph the lowest monthly traffic volume for the year was
observed in March at about 9% below the average. The highest monthly traffic volume for the year was
observed in December at about 6% more than the average.
For this study, traffic counts were undertaken in May and September 2013 outside of school holiday period.
There is no implication of seasonal variation on traffic data used in the traffic modelling.
Figure 3.4 Seasonal variation of traffic on M1 Pacific Motorway at Reeves Road overpass
3.4.5 Peak hour traffic volumes
Figure 3.5 and Figure 3.6 show peak hour traffic volumes on the M1 Pacific Motorway and associated ramps
with Central Coast Highway, Wisemans Ferry Road and Peats Ridge Road for the AM and PM peaks
respectively. The traffic data shows that the Central Coast Highway and the M1 Pacific Motorway carry
similar amounts of traffic north of the Kariong interchange. The following points are noted:
M1 Pacific Motorway carries about 5,000 vehicles per hour (two-way) during the morning peak and
about 5,800 vehicles per hour (two-way) during the afternoon peak just south of the Kariong
Interchange.
During the morning peak southbound on the M1 motorway is the peak direction. During the afternoon
peak northbound on the M1 motorway is the peak direction.
Heavy traffic (1,800 vehicles per hour) is observed on the southbound entry ramp at Kariong
interchange. The entry ramp traffic merges with southbound traffic (1,700 vehicles per hour) on the M1
mainline during the morning peak.
Heavy northbound traffic (1650 vehicles per hour) is observed at the northbound exit ramp at Kariong
interchange during the evening peak.
Figure 3.5 Existing morning peak hour turning volumes
Figure 3.6 Existing afternoon peak hour turning volumes
3.4.6 Heavy vehicles
Table 3.3 below shows the daily number of heavy vehicles counted in 2013 by RMS. The heavy vehicles
were counted on Kariong interchange, Somersby interchange and Central Coast Highway, south of
Wisemans Ferry Road.
Table 3.3 Total vehicles and heavy vehicles per day in study area
Source: 2013 Traffic Counts by RMS.
The existing number of heavy vehicles in the study area ranges from 100 to 3000 vehicles depending on
locations. About 3000 heavy vehicles were recorded on Central Coast Highway immediately south of
Wisemans Ferry Road. Of that about 1000 heavy vehicles used Wisemans Ferry Road entry and exit ramps.
The remaining 2000 heavy vehicles used entry and exit ramps with the Central Coast Highway. The Peats
Ridge Road entry and exit ramps at Somersby interchange carried about 100 to 200 heavy vehicles. The
data in Table 3.3 shows that Kariong interchange carried the largest amount of heavy vehicles.
When the percentage of heavy vehicles is considered, the data shows that about 8% heavy vehicles used
the Kariong ramps. The percentage of heavy vehicles at Somersby interchange was found high between
18% and 20% due to overall low volumes of traffic using this interchange.
By comparison the percentage of heavy vehicles on M1 Pacific Motorway north of Doyalson Link Road
interchange was found between 10% and 13% (sourced from M1 upgrade, Tuggerah to Doyalson, Parsons
Brinckerhoff Study).
3.5 Expected future traffic volumes
The expected year 2039 traffic volumes are shown in the tables below.
Table 3.4 Year 2039 freeway AM peak volumes
Section Time period Direction Volume (vehs/hour)
North of Kariong
Section Time period Volume (vehs/hour)
Kariong NB entry ramp
Kariong SB entry ramp
Kariong NB exit ramp
7.00–8.00
504
480
2319
2147
663
617
618
599
North of Kariong
Table 3.7 Year 2039 Kariong interchange PM peak volumes
Section Time period Volume (vehs/hour)
Kariong NB entry ramp 15.00–16.00 803
16.00–17.00 699
16.00–17.00 840
16.00–17.00 2104
16.00–17.00 612
4. Traffic modelling process
4.1 Previous modelling
Hyder Consulting Pty Ltd (Hyder) was recently commissioned by RMS to undertake a study to develop a
road based traffic model to assess the performance of M1 Pacific Motorway, its ramps and adjacent surface
intersections on Central Coast Highway. The purpose of the study was to assess the performance of
M1 Pacific Motorway between the Kariong and Somersby interchanges (approximately 8 km in length) and
the performance of Kariong interchange with the proposed upgrades.
A road based micro-simulation traffic model was developed for the study area. For the micro-simulation
model, Hyder used Paramics software. Paramics provided an assessment tool that identified:
key network issues that affect the performance of M1 Pacific Motorway
long term options for improvements to traffic flow, including an assessment of the likely performance of
each option.
Parsons Brinckerhoff was provided with the models created by Hyder to perform further analysis. Parsons
Brinckerhoff subsequently reviewed and refined those models to undertake this investigation. Review
comments are described in section 4.4 of this report.
4.2 Modelling purpose and scenarios
The purpose of this modelling investigation is to:
review and fine tune the year 2013 existing conditions Paramics model prepared by Hyder Consulting
review and fine tune the year 2039 base case (do nothing) model
review and fine tune the year 2039 Option 2b model plus refinements
undertake sensitivity testing for the year 2039 do nothing scenario for increased truck traffic (high/low
growth rates?)
undertake sensitivity testing for the year 2039 Option 2b model plus refinements increased truck traffic
(high/low growth rates?)
undertake modelling for the construction staging at year 2013 of each major stage of the program to
predict traffic effects
4.3 Modelling assumptions
The contents of this section 4.3 have been directly extracted from the report by Hyder Consulting previously
referred to in section 1.1 of this report.
4.3.1 Traffic growth
Hyder Consulting’s report summarises traffic growth on the M1 Pacific Motorway between the Kariong and
Somersby interchanges. The traffic modelling study required forecast volumes on the M1 Pacific Motorway in
three future years. For modelling purposes, 2019 was assumed to be the opening year. Traffic forecasts
were then prepared for year 2029 (10 years after opening) and year 2039 (20 years after opening).
Hyder Consulting’s traffic forecast is based on trends obtained from historical AADT and future land use
growth in the M1 Pacific Motorway catchment areas. The catchment area for M1 was determined using
Hyder Consulting’s own Central Coast Strategic Model (TransCAD). Hyder’s traffic forecast was compared
with RMS’s EMME Model where relevant.
4.3.1.1 Historical traffic growth
Historical traffic data between 1998 and 2013 (15 years) for M1 Pacific Motorway were obtained from the
nearest RMS count station 52.982 (M1 at Reeves Road Overpass). Figure 4.1below shows historical AADT
on M1 Pacific Motorway at Reeves Road Overpass as Light Blue line. The historical data indicates that on
average traffic volume on M1 Pacific Motorway at Reeves Road has increased from approximately
43,800 vehicles per day in 1998 to 55,100 vehicles per day in 2013.
A regression model was developed using 15 years continuous AADT data. The regression model has been
used to extrapolate growth until 2039. This is shown as Green Line. The AADT data indicates that between
1998 and 2013 traffic on M1 at this section has grown by 1.5% per annum for a period of 15 years.
Red line shows forecast AADT using Hyder Consulting’s own Strategic Model based on future land use
predicted in Central Coast Regional Strategy. The land use growth is discussed in the following section 4.2.
Figure 4.1 Projected AADT growth on M1 Pacific Motorway between Kariong and Somersby
4.3.1.2 Future traffic growth
The Central Coast Regional Strategy (2006–2031) identifies that the population of the Central Coast is
expected to grow by more than 100,000 to 400,000 residents by 2031. The future background traffic growth
on M1 Pacific Motorway between Kariong and Somersby has been estimated using Hyder Consulting’s own
Central Coast Regional Strategic Model (CCTM, built in TransCAD software). The CCTM model is based on
population and employment growth predicted in the Central Coast Regional Strategy.
The catchment area for population and employment growth within the study area is defined by 34 travel
zones (TZ) as shown in Figure 4.2. The catchment area of M1 Pacific Motorway between Somersby and
Kariong has been determined using select link for 2031 AM peak model. Figure 4.2 also shows likely origin-
destination of trips such as Wyong Road, Sparks Road that use the subject M1 Pacific Motorway section.
Figure 4.2 Catchment area of M1 section between Somersby and Kariong (2031 AM peak model)
Table 4.1 shows projected population and employment growth for catchment areas of M1 Pacific Motorway
from the Kariong to Somersby interchanges between 2006 and 2036. Within the catchment areas, the
population and employment growth is predicted in the order of 1.1% to 1.3% until 2036.
Table 4.1 Population and employment growth within catchment area
Source: BTS August 2012 Release, Catchment area as shown in Figure 4.2
Table 4.2 shows forecast AADT on M1 Pacific Motorway between the Kariong and Somersby interchanges in
opening year 2019, 2029 (10 years after opening) and 2039 (20 years after opening).
Table 4.2 Forecast AADT on M1 Pacific Motorway between Kariong and Somersby
At opening 2019, traffic on the subject M1 Pacific Motorway section is projected about 60,000 vehicles per
day. In 2039 (20 years after opening), traffic on the M1 Pacific Motorway is forecast in the order of
73,600 vehicles per day.
Hyder Consulting’s modelling assessment found that traffic growth on M1 Pacific Motorway between the
Kariong and Somersby interchanges was about 1.5% per annum between 2019 and 2029. The growth is
forecast to reduce to 1.1% per annum between 2029 and 2039. Hyder Consulting’s predicted growth rate
was compared with data contained in RMS’s EMME model. The previous Figure 4.1 showed traffic forecast
sourced from EMME model. When forecast is compared for the longer term between 2013 and 2039, both
TransCAD and EMME models showed similar outcome. The EMME2 forecast at opening year (2019) and
intermediate year (2029) appears to be higher than TransCAD forecast. As agreed with RMS, the predicted
annual growth rate shown in Table 4.2 was adopted for future years modelling purpose.
4.4 Review comments
After reviewing the Hyder Consulting models provided by RMS the following refinements were made:
lane restrictions were placed along the M1 to prevent heavy vehicles from travelling in the right hand
lane
the gradient on the M1 at southern end of freeway was adjusted to match the existing gradient
speeds on Wisemans Ferry Road were adjusted to reflect the existing speed limits
the interchange ramps were re-coded using the Paramics Ramp function
Wisemans Ferry Road/Northbound on ramp intersection was re-coded to reflect existing layout
lane choice on Woy Woy Road, and the Central Coast Highway interchange was adjusted to match
observed behaviour
4.5 Base case model calibration and validation
Whilst the model has undergone a certain amount of refinement, the extent and magnitude of the changes
were considered to be minor and further to discussions with RMS, recalibration and validation of the model
was not deemed necessary by RMS. The model was therefore considered to be suitable as the basis for
further investigations into construction staging and future operating conditions.
4.6 Traffic performance criteria
4.6.1 Main carriageway segments
The performance of the main carriageway segments will be assessed by comparing travel times and level of
service criteria. Travel times are derived from the Paramics model and are measured between the middle of
the Kariong interchange and the middle of the Somersby interchange.
The criteria in Table 4.3 below describe the level of service operating conditions within the traffic stream as
traffic density increases.
Level of Service
≤ 7 Free flow operations
> 7–11 Free flow speeds are retained and ability to manoeuvre is slightly restricted
> 11–16 Flow with speeds near the free flow speeds and ability to manoeuvre is noticeably restricted
> 16–22 Speeds fall with increasing flow and ability to manoeuvre is seriously limited. Minor incidents can cause flow breakdown and queues
> 22 Operation is at capacity with little room to manoeuvre in the traffic stream. Incidents can produce serious queuing and flow breakdown
Demand Breakdown or unstable flow exceeds capacity
> 28.0
4.6.2 Merge and diverge segments
The criteria in Table 4.4 below describe the operating conditions within the traffic stream within the area of
influence of a ramp as traffic density increases for each level of service.
Table 4.4 Level of Service criteria for merges and diverges
Level of Service
> 12–17 Influence area speeds begin to decline
> 17–22 Influence area turbulence becomes intrusive
> 22 Turbulence felt by virtually all drivers
Demand exceeds Ramp and freeway queues form capacity
Source: Highway Capacity Manual 2010 – Transportation Research Board
4.6.3 Intersections
Table 4.5 provides the LoS criteria for intersections. Levels of service range from LoS A (indicating good
intersection operation) to LoS F (indicating over-saturated conditions with long delays and queues). At
signalised and roundabout intersections, the LoS criteria relate to average intersection delay (seconds per
vehicle). At priority controlled (give-way and stop controlled) intersections, the LoS is based on delay
(seconds per vehicle) for the most delayed movement.
Table 4.5 Level of Service criteria for intersections
Level of Service
Traffic signals, roundabout Give Way and stop signs
A Less than 14 Good operation Good operation
B 15 to 28 Good with acceptable delays and spare capacity
Acceptable delays and spare capacity
C 29 to 42 Satisfactory Satisfactory, but accident study required
D 43 to 56 Operating near capacity Near capacity and accident study required
E 57 to 70 At capacity. At signals, incidents would cause excessive delays. Roundabouts require other control mode.
At capacity; requires other control mode
F Greater than 71 Unsatisfactory with excessive queuing Unsatisfactory with excessive queuing; requires other control mode
Source: RMS Guide to Traffic Generating Developments, 2002
5. Existing modelled network performance
As previously noted in section 4.5, since the model has only undergone minor change and refinement,
recalibration and validation of the model was not deemed necessary. The model was therefore considered to
be suitable as the basis for further investigations into future operating conditions.
In order that future scenarios and options can be assessed, benchmark performance characteristics under
the 2013 traffic demand volumes were extracted from the base model.
5.1 M1 Pacific Motorway
The performance characteristics selected for assessment of the freeway are:
travel time
main carriageway speeds
The details of the Paramics model outputs for the base network under the year 2013 demands are listed in
the tables below. As appropriate the HCS2010 - Version 6.5 highway capacity software has been used to
determine expected levels of service (LoS) to supplement the Paramics model outputs. Details of the
analytical outputs are contained in Appendix A.
Travel time
Section Time period Direction Travel time
Between Somersby and Kariong Interchanges 6.00–8.00 NB 03.50
SB 04.44
Between Somersby and Kariong Interchanges 15:00-17:00 NB 04.15
SB 04.37
The southbound travel time is the same for both peaks. However, the travel time for northbound travel is
longer for the evening peak reflecting the higher traffic volumes and the interaction between cars and trucks.
Freeway and ramp performance
Section Time period Direction Link speed (km/h) LoS
North of Kariong Interchange
SB 94 C
SB 97 B
SB ≥ 110 B
SB ≥ 110 B
Section Time period Link speed (km/h) LoS
Kariong NB exit ramp 6.00–7.00 ≥ 110 B
7.00–8.00 ≥ 110 B
7.00–8.00 ≥ 110 B
7.00–8.00 100 C
7.00–8.00 36 D
Section Time period Direction Link speed
(km/h) LoS
SB 96 B
SB 97 B
South of Kariong
SB ≥ 110 A
SB ≥ 110 A
– –
– –
Table 5.6 PM Kariong interchange ramp performance 2013 Base
Kariong NB exit ramp 15.00-16.00 102 D
16.00-17.00 104 D
16.00-17.00 109 B
16.00-17.00 102 B
16.00-17.00 49 B
The performance characteristics selected for assessment of the intersections are Level of Service (LoS) and
delay. SIDRA INTERSECTION – Version 5.1 has been used to analyse intersections.
Table 5.7 AM intersection performance 2013 Base
Intersection
CCH_Wisemans Ferry Road
Intersection
5.3 Discussion
AM peak
For southbound travel the analysis shows that the freeway performs well during the critical AM peak with the
lowest LoS at C. Link speeds are expected to be between 95 km/h and 100 km/h. This represents good
operation with room for growth and/or changes in travel patterns.
The southbound exit ramp is expected to operate at LoS C and the northbound entry and exit ramps at
LoS B. This represents good operation.
However, where the Kariong southbound entry ramp drops to one lane, there is considerable turbulence and
delay leading to queues spilling back to the Central Coast Highway/Wisemans Ferry Road intersection. Level
of Service analysis shows the southbound entry ramp merge is operating at the bottom of LoS D and very
close to capacity with link speeds around 35 km/h during the critical AM peak. It is important to note that the
congestion is confined to the arterial network and does not affect operation of the motorway main
carriageways.
The Central Coast Highway intersections are expected to operate at LoS C or better with overall delays less
than 40 seconds.
PM peak
For northbound travel the analysis shows that the LoS on the main carriageway is LoS C south of the
Kariong interchange and LoS B to the north of the interchange. Link speeds south of the Kariong interchange
are between 85 and 90km/h and between 95 and 100 km/h to the north of the interchange. This represents
satisfactory operation. For southbound travel on the main carriageway link speeds are between 95 and
100 km/h north of the interchange at LoS B and at the speed limit to the south of the interchange at LoS A.
The northbound entry ramp and the southbound entry and exit ramps are expected to operate at LoS B with
link speeds between 100 km/h and the speed limit.
At the northbound exit turbulence is evident, caused by the speed differential as faster light vehicles weave
through the slower heavy vehicles ascending the grade in the left lane to gain access to the exit ramp
auxiliary lane. Link speeds are expected around 100 km/h and operation at LoS D. This represents operation
close to capacity with little room for changes in travel patterns or growth.
The Central Coast Highway intersections are expected to operate at LoS D or better with overall delays less
than 50 seconds
6. Future modelled network performance
The project proposes to upgrade the Kariong interchange and to make the M1 six lanes between Kariong
and Somersby. The proposed upgrades are described below and detailed in Figure 6.1.
widen the two lane section of the northbound carriageway to three lanes up to the Somersby
interchange
widen the southbound carriageway from two to three lanes between the Somersby interchange and just
north of Wisemans Ferry Road
extend the northbound exit ramp lane to create extra storage
provide a second added lane to the southbound entry ramp with a 300 m auxiliary lane
extend the northbound entry ramp lane by 300 m
provide traffic signals at the Wisemans Ferry Road/northbound entry ramp terminal
Source: Hyder Consulting Pty Ltd
Figure 6.1 Proposed upgrades in option 2B
-
-
-
-
The base network was assessed under the year 2039 traffic demands to identify areas exhibiting operational
problems and poor traffic performance.
After that initial modelling three further options were also considered. Option 2B was modified to create the
options shown below:
Option 2B-a:
the means of traffic control at the northbound entry ramp terminal has been changed from traffic
signals to priority control
Option 2B-b:
the means of traffic control at the northbound entry ramp terminal has been changed from traffic
signals to priority control
the northbound exit lane has been increased in length to 500 m. This is achieved by widening into
the median and remarking the left hand through lane as the exit lane.
Option 3
the northbound exit has been changed to a two lane exit ramp with a 300 m auxiliary lane. This is
achieved by remodelling the exit nose and the ramp beyond, widening into the median and
remarking the left hand through lane as the auxiliary lane.
6.1 Future network assumptions
The future network characteristics for the future base are unchanged from year 2013.
6.2 M1 Pacific Motorway
The details of the model outputs under the year 2039 traffic demands for the base network and the above
options are listed in the tables below.
Travel time
Section Direction Do
Between Somersby and Kariong NB 03:55 03:44 03:41 03:42 03:42
SB 04:58 04:32 04:30 04:29 04:30
Table 6.2 PM travel times 2039
Section Direction Do
Between Somersby and Kariong NB 04:44 04:05 04:02 04:07 04:07
SB 04:56 04:26 04:26 04:28 04:28
- -
–
–
–
–
- -
–
–
–
–
–
–
–
–
S e
c ti
o n
T im
e p
e ri
o d
n
Do nothing Option 2b Option 2b a Option 2b b Option 3
L in
k s
p e
e d
(k m
S
NB ≥ 110 A ≥ 110 A ≥ 110 A ≥ 110 A ≥ 110 A
SB 88 C 102 B 105 B 106 B 104 B
NB ≥ 110 A ≥ 110 A ≥ 110 A ≥ 110 A ≥ 110 A
SB 89 C 104 B 103 B 107 B 102 B
NB ≥ 110 A ≥ 110 A 106 A 113 A ≥ 110 A
SB 109 C 103 C 101 C 102 C 104 C
NB ≥ 110 A ≥ 110 A 109 A ≥ 110 A ≥ 110 A
SB 110 C 104 C 104 C 101 C 104 C
South of Kariong
S e
c ti
o n
T im
e p
e ri
o d
≥ 110 A ≥ 110 A ≥ 110 A 109 A ≥ 110 A
≥ 110 A ≥ 110 A ≥ 110 A ≥ 110 A ≥ 110 A
≥ 110 B ≥ 110 A ≥ 110 A ≥ 110 A ≥ 110 A
≥ 110 B ≥ 110 A ≥ 110 A ≥ 110 A ≥ 110 A
97 C 106 C 107 C 109 C 107 C
97 C 106 C 107 C 109 C 107 C
35 F 57 D 56 D 55 D 56 D
36 F 57 D 56 D 55 D 57 D
- -
-
-
-
-
- -
–
–
–
–
–
–
–
–
Table 6.5 PM freeway performance 2039
Section Time
S
NB 92 C 107 B 107 B 105 B 106 B
SB 89 C 105 B 106 B 103 B 104 B
NB 94 B 108 B 106 B 105 B 108 B
SB 91 C 107 B 106 B 107 B 106 B
NB 48 F 50 F 60 E 72 D 96 D
SB ≥110 B ≥110 B ≥110 B ≥110 B ≥110 B
NB 28 F 26 F 40 F 30 F 96 C
SB ≥110 B ≥110 B ≥110 B ≥110 B ≥110 B
South of Kariong
Section Time
40 F 38 F 34 F 40 F 95 C
34 F 32 F 30 F 25 F 94 C
108 C 109 C 108 C 106 C 105 C
≥110 C 109 C 108 C 105 C 105 C
99 C 107 C ≥110 C 107 C 109 C
99 C 107 C ≥110 C 107 C 109 C
44 A 62 A 62 A 62 A 62 A
47 A 63 A 63 A 63 A 63 A
- -
- -
6.3 Central Coast Highway
The details of the model outputs for the base network under the year 2039 traffic demands are listed in the
tables below.
Intersection Control type
A 9 B 16 A 10 A 10 B 16
Signalised F 161 C 30 C 30 C 31 C 31
CCH_Kangoo Drive Signalised F 140 A 11 A 11 A 12 A 12
CCH_Curringa Road_The Avenue
Signalised F 82 C 42 C 41 C 41 B 26
CCH_Woy Woy Road Signalised E 67 C 37 C 37 C 41 C 38
Table 6.8 PM Intersection performance 2039
Intersection Control
Priority (signalised in
2B & 3) B 16 A 14 B 16 B 16 A 14
Signalised C 29 C 29 C 30 C 29 D 49
CCH_Kangoo Drive Signalised A 11 A 11 B 17 B 15 E 69
CCH_Curringa Road_The Avenue
Signalised D 55 D 54 E 61 E 60 F 112
CCH_Woy Woy Road Signalised C 30 C 32 C 34 C 30 C 30
6.4 Network statistics
The following network statistics have been extracted from the Paramics models.
Table 6.9 Network statistics
Model Vehicle Kilometres Travelled
2039 Future Base AM 186,275 3,124 60 86,438 22,701
2039 Future Base PM 244,073 3,917 62 68,286 29,100
2039 2B AM 186,726 2,296 81 36,342 22,701
2039 2B PM 243,255 3,912 62 68,328 29,100
2039 2B AM no signal 186,788 2,738 68 50,052 22,701
2039 2B PM no signal 243,539 3,931 62 67,929 29,100
2039 2B AM long exit 186,426 2,296 81 35,439 22,701
2039 2B PM long exit 244,186 3,657 67 66,330 29,100
2039 AM dual exit 186,805 2,295 81 36,241 22,701
2039 PM dual exit 244,051 3,279 74 59,987 29,100
6.5 Discussion of performance
6.5.1 Future Base – Do Nothing
The existing (2013) traffic on the M1 Pacific Motorway between the Kariong and Somersby interchanges is
about 55,100 vehicles per day. In the next 25 years traffic is forecast to grow between 1.1% and 1.5% per
annum. In 2039 traffic is forecast to be in the order of 73,600 vehicles per day. At the Kariong interchange
about 2,400 vehicles are forecast to join the motorway via the southbound entry ramp in the morning peak. In
the afternoon peak about 2,200 vehicles are forecast to leave the motorway via the northbound exit ramp.
AM peak – Do Nothing
When compared to the year 2013 existing network performance, the model shows for southbound travel that
travel times have increased by 14 seconds and the LoS has remained at LoS C. Link speeds north of the
interchange have dropped by 6 km/h to 88 km/h but remain at or close to the speed limit to the south of the
interchange. This represents good operation with room for growth and/or changes in travel patterns.
The southbound exit ramp is expected to operate at LoS C, the northbound entry ramp at LoS B and the
north bound exit ramp at LoS A. This represents good operation.
However, where the Kariong southbound entry ramp drops to one lane, there is considerable turbulence and
delay leading to queues spilling back to the Central Coast Highway/Wisemans Ferry Road intersection. Long
delays and queues are predicted on the Central Coast Highway beyond Woy Woy Road as shown in Figure
6.2 below. Level of service analysis shows the southbound entry ramp added lane is operating at LoS F and
with link speeds around 35 km/h during the critical AM peak. It is important to note that the congestion is
confined to the ramp and the adjacent arterial network and does not adversely affect operation of the
motorway main carriageways. Link speeds in the vicinity of the nose are now low due to the increased
demand.
This congestion is also reflected in the poor levels of service at the Central Coast Highway intersections,
shown in Table 6.7 where the maximum overall delay has increased by 130 seconds to 161 seconds.
Figure 6.2 Queues from the Kariong interchange southbound entry ramp merge to the Central Coast Highway
PM peak – Do nothing
For northbound travel the model shows that at year 2039 travel times have increased by 29 seconds from
year 2013 and the LoS has dropped from LoS B to LoS C. Link speeds north of the interchange have
dropped to about 92 km/h. However, south of the interchange link speeds have dropped to around 30 km/h
and the LoS to LoS F. This is caused by the turbulence at the northbound exit which is related to the speed
differential in the main carriageway as faster light vehicles weave through the slower heavy vehicles
ascending the grade in the left lane to gain access to the exit ramp. Operation is expected at LoS F which
represents collapsed flow.
For southbound travel on the main carriageway link speeds have dropped to about 90 km/h north of the
interchange and operation is expected to drop from LoS B to LoS C. South of the interchange link speeds
remain at the speed limit and operation at LoS B.
The analysis shows the northbound entry ramp is expected to operate at LoS C. However it is considered
that this may be optimistic given the short 100m merge and the slow moving truck traffic in the left hand lane
of the main carriageway.
The southbound exit ramp is expected to operate at LoS C with a link speed nearing 100 km/h.
The southbound entry ramp is expected to operate at LoS A at the nose and with a link speed of 47 km/h on
the approach to the nose. It is important to note that as the traffic moves from the two lane section to the one
lane section of the ramp, speeds increase as vehicles leave the front of the queue in the upstream
congested two lane section.
than 55 seconds. It is noted that the model shows long queues on the northbound exit ramp coming from the
Central Coast Highway/Wisemans Ferry Road intersection. However, the queues do not spill back into the
freeway, as shown in Figure 6.3. On this basis it is considered that the proposed widening to extend queuing
space is not warranted.
Figure 6.3 Queues on the northbound exit ramp at the Kariong Interchange
6.5.2 Option 2B
AM peak – Option 2B
When compared to the year 2039 do nothing network performance, the model shows the widened
southbound carriageway has decreased the travel time by 26 seconds, link speeds increased by 15 km/h
and the LoS has risen from LoS C to LoS B.
The southbound exit ramp is expected to operate at LoS C and the northbound entry and exit ramps at
LoS A. This represents good operation.
The Kariong southbound entry ramp is now configured as two added lanes and is expected to operate with
link speeds approaching 60 km/h at LoS D with reduced queuing. Whilst the model shows that vehicles
occasionally have trouble finding gaps, as depicted in Figure 6.4, it is considered that as traffic grows, driver
behaviour will adjust and main carriageway vehicles will tend to keep to the right to permit the entry ramp
traffic to join the stream.
Operation of the Central Coast Highway intersections has improved with the worst overall delay reduced by
130 seconds. The level of service has increased from LoS F to LoS C.
Figure 6.4 Performance of the southbound entry ramp AM 2039
PM peak – Option 2B
For northbound travel the model shows that travel times have decreased by 39 seconds and the LoS has
risen from LoS C to LoS B. Link speeds north of the interchange are 108 km/h. However, south of the
interchange link speeds remain low and LoS F prevails.
For southbound travel on the main carriageway link speeds have increased by about 15 km/h north of the
interchange and operation is expected at LoS B. South of the interchange link speeds are 26 km/h and
operation is at LoS B.
The analysis shows the northbound entry ramp is expected to operate at LoS C with the increased length of
auxiliary merging lane. However, it should be noted that the model also showed the traffic signals at the
ramp terminal created platoons of traffic which had difficulty merging with the slow moving trucks on the main
carriageway as shown in Figure 6.5. Whilst this did not happen every time a platoon of traffic reached the
merge, it highlights a potential operational problem.
At the north bound entry ramp terminal a two phase sequence with a cycle time of 40 seconds was chosen
for operation and the green time is evenly split between the dual right turn to the ramp and the southbound
single lane through movement. Firstly, this arrangement breaks up the larger platoons coming from the
Central Coast Highway leading to smaller platoons of traffic entering the ramp thereby minimising the
influence of the platooned traffic on the merge with the main carriageway. Secondly, the arrangement
minimises overall average delay at the ramp terminal to 14 seconds and operation at LoS A which
represents good operation.
The southbound exit ramp is expected to operate at LoS C respectively with link speeds just under the speed
limit. The southbound entry ramp is expected to operate at LoS A with associated link speeds of 63km/h.
The northbound exit ramp is expected to operate at LoS F since the year 2039 demand is expected to be
2200 vph and cannot be managed in one exit lane. Since the current exit demand is around 1650 vph,
capacity operation would be expected to occur well before the design year.
than 55 seconds.
Figure 6.5 Performance of the northbound entry ramp PM2039
6.5.3 Option 2B-a
The key difference between this option and Option 2B is the means of traffic control at the northbound entry
ramp terminal. Traffic signals in Option 2B operate at LoS B with delays of 20 seconds in both peaks. Priority
control improves the LoS in the AM peak to LoS A with reduced delays. The LoS in the PM peak drops from
LoS A to LoS B but with a 2 second increase in delay to 16 seconds. The LoS for priority control is at least as
good, if not better than, a signalised ramp terminal. It is also noted that priority control supports the delivery
of random arrivals at the merge which will assist ramp traffic to join the main line flow. It is therefore
considered that, from a capacity perspective, the installation of signals is not warranted. However, it is noted
that priority control does not completely prevent platooning with platoons being formed behind slower
vehicles climbing the entry ramp grade.
It is also noted that the left hand lane of the recently installed dual right turn on the Central Coast Highway at
Wisemans Ferry Road is underutilised. This is caused by traffic in the left hand right turning lane having
difficulty moving to the right in Wisemans Ferry Road to turn at the northbound entry ramp terminal. The
provision of a dual turn lane resolves this issue and improves operation and safety.
It is understood that the provision of signals are not within the scope of this project and that they will be
installed at a later date. Once signals are installed, the cycle times should be monitored to determine the
optimum cycle time required to minimise the impact of platoons on the operation of the mainline merge and
achieve acceptable delay at the ramp terminal.
Further, if the traffic platoons are having difficulty finding gaps and merging then the provision of a ramp
meter should be considered.
6.5.4 Option 2B-b
The increased northbound exit lane length is the only difference between this option and those preceding.
The model indicates that the increased exit lane length has little or no effect on the operation at the exit as
shown in Figure 6.6. As noted previously, the year 2039 pm peak demand is expected to be 2200 vph and
cannot be managed in one exit lane. It is considered that whilst the model shows no improvement in
conditions, in reality the extra opportunities to join the exit ramp flow would result in improved operation,
particularly in the years after opening. However, operation would be expected to gradually deteriorate as
flows approached capacity and congestion/collapsed flows would prevail during the PM peaks. These
conditions would also have related safety problems caused by speed differentials. Given that the existing PM
peak exit flow is around 1650 vph these conditions could be expected to occur in the near future.
Figure 6.6 Performance of the northbound exit ramp with 500 m exit lane
6.5.5 Option 3
Provision of a two lane exit at the northbound exit requires the addition of an auxiliary lane. Since widening
outside of the formation is not desirable the extra pavement could be provided in the median. The through
traffic lanes would be shifted by one lane to the right to allow the left hand lane to become the auxiliary lane.
At the nose a second exit lane would connect to the ramp. Beyond the exit the through lanes would then be
moved one lane to the left to re-join the main carriageway alignment.
The two lane exit and 300 m long auxiliary lane significantly improve operation during the critical pm peak.
The expected LoS has risen from LoS F to LoS C and link speeds have risen to 95 km/h. It is noted that
whilst the heavier commercial vehicles will continue to operate at crawl speeds through the interchange site
the through vehicles are now in the lane adjacent to the auxiliary lane. This will assist in creating gaps and
opportunities for vehicles to diverge to the exit from the main lanes.
The northbound entry ramp continues to operate at LoS C.
The improved conditions on the approach to the exit ramp are shown in Figure 6.7 below.
During the PM peak the Central Coast Highway is expected to incur extra delay due to the improved
conditions on the exit ramp as traffic is no longer constrained at the exit from the motorway. The maximum
expected increase in delay is 90 seconds at the Woy Woy road intersection. Operating LoS is expected to be
LoS F.
Figure 6.7 Performance of the northbound two lane exit ramp
6.6 Sensitivity
To test the sensitivity of the design, Option 3 was run under a lower demand scenario. For the sensitivity
analysis, the new demand was calculated by assuming the predicted demand would not be met until 2049,
and then extrapolating a new 2039 demand from that assuming a linear growth rate.
Table 6.10 AM travel times 2039 sensitivity
Between Somersby and Kariong interchanges 6.00–8.00 NB 03:41
SB 04:26
Between Somersby and Kariong interchanges 15.00–17.00 NB 04:03
SB 04:25
North of Kariong interchange
SB 106 B
SB 106 B
SB 104 C
SB 107 C
Kariong NB exit ramp 6.00–7.00 ≥110 A
7.00–8.00 ≥110 A
7.00–8.00 ≥110 A
7.00–8.00 107 C
7.00–8.00 56 B
North of Kariong
SB 106 B
SB 106 B
South of Kariong
SB ≥110 B
SB ≥110 B
Table 6.15 PM Kariong interchange ramp performance 2039 sensitivity
Kariong NB exit ramp 15.00–16.00 91 B
16.00–17.00 97 B
16.00–17.00 105 C
16.00–17.00 ≥110 B
16.00–17.00 62 A
6.6.1 Central Coast Highway
Intersection Control type LoS Delay
Wisemans Ferry Road_NB entry ramp Signalised A 14
CCH_Wisemans Ferry Road Signalised C 30
CCH_Kangoo Drive Signalised A 11
CCH_Curringa Road_The Avenue Signalised B 25
CCH_Woy Woy Road Signalised C 36
Table 6.17 PM intersection performance 2039 sensitivity
Intersection Control type LoS Delay
Wisemans Ferry Road_NB entry ramp Signalised A 14
CCH_Wisemans Ferry Road Signalised D 48
CCH_Kangoo Drive Signalised E 67
CCH_Curringa Road_The Avenue Signalised F 110
CCH_Woy Woy Road Signalised B 26
It is evident from the outputs that the Kariong interchange performs better under the reduced demand than
under the higher demand. It is also noted that whilst the Central Coast Highway intersections show slight
improvements during both peaks, capacity operation remains east of Wisemans Ferry Road during the PM
peak under the heavy east bound demand.
7. Crash analysis This section presents a crash data analysis of the Pacific Motorway over a five year period and identifies the
impacts on road safety based on the concept design of the proposed Pacific Motorway widening between the
Kariong and Somersby interchanges.
The purpose of the crash data analysis was to determine the existing rate of crashes in the study area as
well as to identify the number of crashes that would be affected by the proposed improvements.
7.1 Review of previous crash reduction analysis
Hyder Consulting has prepared a crash data analysis for the M1 Pacific Motorway widening between the
Kariong and Somersby interchanges in December 2013 for Roads and Maritime Service (RMS). The crash
history and existing conditions described in Hyder’s ‘M1 Pacific Motorway Widening Between the Kariong
and Somersby Interchanges, Crash Data Analysis – Addendum 1’, referred to in this section and have been
reviewed.
The assumptions and findings that were made by Hyder Consulting for the crash reduction analysis are
considered to be fair and reasonable and have been replicated in this section. However, there are limitations
in forecasting crash reduction associated with the proposed improvements in Hyder’s analysis. This is mainly
due to the difficulty in pinpointing the location of reported crashes that occurred on the proposed widening
section of the M1 motorway carriageways and ramp sections as opposed to crashes that occurred on the
adjacent road network, such as the Central Coast Highway and Wisemans Ferry Road.
As the crash map (refer Appendix B) does not provide any consistent indication in these respects, Parsons
Brinckerhoff has obtained the digital copy (Shape file format) of the crash map to identify the location of each
crash and to identify the crashes that would be affected by the proposed improvements.
7.2 Crash history
The crash data was obtained from RMS for the five year period between 1 October 2007 and 30 September
2012 to estimate the recent crash patterns for the Pacific Motorway between the Kariong and Somersby
interchanges including the motorway on and off-ramp sections. It should be noted that the crash data on the
following road sections were not considered in this crash analysis:
M1 Pacific Motorway, north of northbound off-ramp of the Somersby interchange
on and off-ramp section of the Somersby interchange
Central Coast Highway, south of the Central Coast Highway and Wisemans Ferry Road intersection
Wisemans Ferry Road, between its intersections with Central Coast Highway and Pacific Highway.
Refer to Appendix B for the raw RMS crash data.
A review of the crash data indicates that 106 reported crashes have been recorded on the assessed road
sections. These include 38 injury crashes and 68 non-casualty crashes, but no fatal crashes. The crashes
are classified as shown in Table 7.1.
-
Table 7.1 Summary of crash data (October 2007 to September 2012)
Total number of crashes
Killed Injured
106 0 (0.0%) 38 (35.8%) 68 (64.2%) 48 0 (0.0%) 48 (100.0%)
Analysis of the location of recorded crashes indicated that:
101 out of 106 crashes (95.3%) occurred on the Pacific Motorway carriageways including:
35 injury crashes
66 non-casualty crashes
five out of 106 crashes (4.7%) occurred on the on and off ramp sections of the Kariong Interchange
including:
7.3 Predominant crash types
Analysis of the type of crashes on the Pacific Motorway indicates:
over the five year period, the most common crashes resulted in the vehicle losing control (off
carriageway on straight and curve). 59 out of 106 crashes (55.7%) occurred along the Pacific Motorway
between Kariong and Somersby Interchanges
rear-end crashes were the second most common crash type. 24 out of 106 (22.6%) were reported as
rear-end type crashes
a total of 11 (10.4%) lane change collisions occurred.
Figure 7.1 shows the number of crashes per crash movement within the study area for the period between
1 October 2007 and 30 September 2012.
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Figure 7.1 Crash movements on the Pacific Motorway between Kariong and Somersby interchanges
Table 7.2 shows crash rate data estimated for the section of M1 Pacific Motorway. The overall crash rate for
the subject section of motorway was found to be 6.7 crashes per 100 million vehicle kilometres travelled
(100 MVKT).
Table 7.2 Existing crash rate on the subject section of the M1 Pacific Motorway
Crash type No. of crashes per year No. of crashes (per 100 MVKT)
Crash rate (per km/year)
Non casualty crashes
21.2 6.7 1.34
7.6 2.4 0.48
13.6 4.3 0.86
7.4 Crash savings
An impact on road safety would occur as a direct result the following improvements proposed under Option 3
of the M1 Pacific Motorway:
Improvement 1: additional travel lane for the northbound and southbound carriageways of the Pacific
Motorway (two lanes section of the carriageway to three lanes) between the Kariong and Somersby
interchanges
Improvement 2: additional entry lane for the southbound on-ramp from the Central Coast Highway to the
Pacific Motorway
Improvement 3: extension of the northbound on-ramp lane from Wisemans Ferry Road to the Pacific
Motorway by 300 m
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Improvement 4: provision of a two lane exit and auxiliary lane for the northbound off-ramp from the
Pacific Motorway to the Central Coast Highway.
The RMS’s Accident Reduction Guide Part 1: Accident Investigation and Prevention (2004) was used as a
guide for estimating the changes in crash frequency as a result of each improvement. Table 7.3 shows the
impact on road safety associated with the concept design, based on the Appendix C of the RMS document
provides crash reduction percentages that can be applied for a wide range of road safety improvements.
Table 7.3 Impact on road safety
Location No. of crashes occurred at this location by DCA type (between October 2007 and September 2012)
Percentage reduction in crashes by DCA type (based on RMS guide and assumption)
Improvement 1 Provision of an additional travel lane on the Pacific Motorway in each direction (Widen the two lanes section of the motorway to three lanes)
Pacific Motorway DCA 301: eight injury crashes and 13 non- 30% reduction in crashes involving off between the Kariong casualty crashes carriageway on straight section and off interchange and
DCA 304: one injury crash and one non- carriageway on straight then hit object
Somersby interchange casualty crash
(DCA 700 series) (include merging and diverging area to and from on and off
DCA 305-307: four injury crashes and seven non-casualty crashes
20% reduction in crashes involving off carriageway on curve section and off carriageway on curve then hit object
sections) DCA 701-702: one injury crash and
one non-casualty crash
Other DCA: two injury crashes and 10 non- casualty crashes.
(DCA 800 series)
15% reduction for rear-end crash type (DCA 300 series).
Impact on road safety as a result of the proposed upgrade
Note that the Roads and Maritime accident reduction guide does not consider road widening as a crash reduction factor alone. Therefore it was proposed to assess the impact of ‘overtaking/climbing lanes’ treatment to consider the road widening.
A third lane would effectively increase the ‘clear zone’ and recoverable road space for lanes two and three for run-off- road to the left crashes. Therefore, the provision of an additional travel lane on the motorway is predicted to reduce off carriageway type crashes by 20 to 30% for single vehicle accidents.
In addition, the added lane onto the four-lane dual carriageway will reduce the traffic density per lane, and with that it was assumed that there would be 15% reduction in rear-end crash events.
Improvement 2 additional entry lane for the southbound on ramp
Southbound on-ramp DCA 301: one injury crash and one non- 30% reduction for rear-end crash type from the Central Coast casualty crash within the on-ramp section (DCA 300 Highway to the Pacific series) Motorway
The proposed additional lane on the southbound on-ramp will increase the capacity of the ramp which will result in:
reduced traffic density in each on-ramp lane, until future traffic volume growth starts to displace this benefit
reduced risk of queues spilling back into the Central Coast Highway.
In comparing the crash reduction potential of an additional carriageway lane versus that of on-ramp lane, it is likely
that such a treatment could reduce crashes by 30%.
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– -
Location No. of crashes occurred at this location by DCA type (between October 2007 and September 2012)
Percentage reduction in crashes by DCA type (based on RMS guide and assumption)
Improvement 3 extension of the northbound on ramp lane by 300m
Northbound on-ramp from the Wisemans Road to the Pacific Motorway
No reported crash on this section 30% reduction for rear-end crash type within the on-ramp section (DCA 300 series)
The increase in length of the ramps is likely to reduce rear-end crash potential. In the case of the northbound on-ramp, the increased length of on-ramp allows more of the vehicle’s acceleration profile to be fully accommodated in, and protected by, the acceleration lane.
The RMS guide suggests that improved acceleration facilities (such as seagull intersections) have the potential to reduce rear-end crashes by 50–60%. Similarly, as the subject assessment is a case of increasing the length of existing acceleration facilities, a more conservative 30% reduction has been adopted.
Improvement 4 two lane exit lane for the northbound off ramp
Northbound off-ramp from the Pacific Motorway to the Central Coast Highway
DCA 301: one injury crash and one non- casualty crash
30% reduction for rear-end crash type within the off-ramp section (DCA 300 series)
Under the existing layout, exiting vehicles may be forced to commence braking in the upstream through lane as they approach the exit thereby increasing rear-end crash risk, crashes related to differentials in speed and crashes involving lane changes on the main carriageway.
The proposed two lane exit at the northbound exit ramp includes the addition of an auxiliary lane. The provision of an auxiliary lane would be expected to reduce turbulence on the approach to the exit and at the exit point itself. Speed differentials between the through and exiting vehicles would also be expected to be reduced leading to improved operation and safety outcomes.
The proposed two lane exit and auxiliary lane would also assist in creating gaps and opportunities for vehicles to diverge to the exit from the main lanes as all through traffic is no longer in the left most lane. This would allow more of an exiting vehicle’s deceleration profile to be fully accommodated in, and protected by, the auxiliary lane.
The RMS guide suggests that the provision of a deceleration facility could result in 60% reduction in rear-end crashes. However, this is the reduction rate where there is no deceleration facility to begin with. As such, the additional crash reduction of additional exit lane with an increased length of a deceleration facility was conservatively assumed to be 30%.
Source: Roads and Maritime’s Accident Reduction Guide Part 1: Accident Investigation and Prevention (2004)
(1) DCA stands for Definition of Coding Accidents
It should be noted that crash savings have not been applied for crashes that occurred on the following non-
widening section of the M1 motorway carriageways:
existing three lane section of the northbound carriageway between the Kar

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