Transport Assessment – what it is and why

we do it

Transport Assessment – what it is and why

we do it

Tom Rye, Professor of Transport Policyand Mobility ManagementTransport Research InstituteEdinburgh Napier University

The changing face of TIAs/TAsThe changing face of TIAs/TAs

Was…

Traffic Impact Assessment of a new development

Vehicle trips only

catering for predicted trips

Was…

Traffic Impact Assessment of a new development

Vehicle trips only

catering for predicted trips

Now …

Transport (Impact) Assessment of a new development

All trips by all modes

managing predicted trips

Now …

Transport (Impact) Assessment of a new development

All trips by all modes

managing predicted trips

Why this changed approach to Transport Assessment?Why this changed approach to Transport Assessment?

Key Elements of a TAKey Elements of a TA

Extract: Transport Assessment and Implementation: A Guide, Scottish Executive, 2005

Thresholds for TA (UK)Thresholds for TA (UK)

Extract: Transport Assessment and Implementation: A Guide, Scottish Executive, 2005

TA ProcessTA Process Trip generation

Mode share

Travel Plan

Monitoring

Assignment

Junction Analysis

Internal site design

Car parking

Trip Generation and Mode ShareTrip Generation and Mode Share

How many people will travel to a development, by which modes?

Survey existing developments

Build databases

Databases give average trips and mode share per 100 sq metres

Examples:

• TRICS – www.trics.org (trial version available)

• TRAVL – www.travel.org

Mode share – influences impact of development on transport network

How many people will travel to a development, by which modes?

Survey existing developments

Build databases

Databases give average trips and mode share per 100 sq metres

Examples:

• TRICS – www.trics.org (trial version available)

• TRAVL – www.travel.org

Mode share – influences impact of development on transport network

ParkingParking

Clear link between:• Parking at and around

development and

• Mode share and so impact of development on network

Better practice:• Maximum parking standards

• Parking related to public transport accessibility

• Managed parking on site

• On-street controls around site

Clear link between:• Parking at and around

development and

• Mode share and so impact of development on network

Better practice:• Maximum parking standards

• Parking related to public transport accessibility

• Managed parking on site

• On-street controls around site

Trip distribution, assignment, junction assessmentTrip distribution, assignment, junction assessment

Distribution

Where do people who use development come from – from which directions?

Are they making a special trip or just passing by?

Both affect impact of development on network

Assignment – which routes people take locally to reach development?

Assessment – impact of new traffic on junctions near development?

Distribution

Where do people who use development come from – from which directions?

Are they making a special trip or just passing by?

Both affect impact of development on network

Assignment – which routes people take locally to reach development?

Assessment – impact of new traffic on junctions near development?

Influencing mode shareInfluencing mode share Managing how people travel to/from

development How?

• Site location

• Thinking about accessibility by all modes

• Parking (charging?)

• Site layout

• Improve alternative modes

• Travel Plans (MM/TDM built in from planning stages)

If fewer people travel by car to development, puts less strain on existing road network, fewer new roads needed

BUT – key part of TA can be new/improved junctions to access development

Managing how people travel to/from development

How?• Site location

• Thinking about accessibility by all modes

• Parking (charging?)

• Site layout

• Improve alternative modes

• Travel Plans (MM/TDM built in from planning stages)

If fewer people travel by car to development, puts less strain on existing road network, fewer new roads needed

BUT – key part of TA can be new/improved junctions to access development

Entrance closer to pedestrian routes

Developer paid for new junction and pedestrian crossings

Supermarket close to very frequent bus routes

Entrance/exit from car park not on main road

Car park behind building

Entrance closer to pedestrian routes

Developer paid for new junction and pedestrian crossings

Supermarket close to very frequent bus routes

Entrance/exit from car park not on main road

Car park behind building

Some of these ideas in practiceSome of these ideas in practice

MM measures – could be part of TAMM measures – could be part of TA

What has MM as part of TA

achieved?

What has MM as part of TA

achieved? Allowed developments to

go ahead that otherwise would not

Reduced traffic impacts of new developments (and so cost to developers)

Improved accessibility for all

Allowed developments to go ahead that otherwise would not

Reduced traffic impacts of new developments (and so cost to developers)

Improved accessibility for all

Example - Sihlcity, ZurichExample - Sihlcity, Zurich

Sihlcity, Zurich – key dataSihlcity, Zurich – key data

area m2 41’990

construction period 30.06.2003 - 22.03.2007

volume of investment Mio. € 600

rental revenue p.a. Mio. € 30

total rentable area (without parking) m2 97’000

rentable area for shops m2 41’000

rentable area for services m2 24’000

rentable area for culture, cinema, hotels m2 19’000

rentable area shopping, fitness / wellness, apartments, stocks

m2 13’000

number of working places 2’300

visitors per day (average between 22.03 and 30.06) 19’000

number of parking spaces 850

Sihlcity, Zurich: Accessibility with different modesSihlcity, Zurich: Accessibility with different modes

Sihlcity, Zurich - requirements to obtain planning permission, 2002Sihlcity, Zurich - requirements to obtain planning permission, 2002

Public transport: financial contribution to extended PT and new PT stops

600 bike parking spaces “recreational quality” guarantee for

pedestrians Developer paid for new access ramp to main

road Parking limited to 805 PP and 50 P+R Trip quota: limit on monthly car trips

generated by development Home delivery service defined in the area specific land use plan of

Sihlcity and agreement between investor/ground owner and environmental association

Achieved: 90% trips non-car

Public transport: financial contribution to extended PT and new PT stops

600 bike parking spaces “recreational quality” guarantee for

pedestrians Developer paid for new access ramp to main

road Parking limited to 805 PP and 50 P+R Trip quota: limit on monthly car trips

generated by development Home delivery service defined in the area specific land use plan of

Sihlcity and agreement between investor/ground owner and environmental association

Achieved: 90% trips non-car