GREEK

GUIDELINES FOR

SETTING SPEED

LIMITS

B. Psarianos, S. Palaskas, Nat’l Techn. Univ. Athens, Greece

N. Stamatiadis, Univ. of Kentucky, U.S.A.

SPEED LIMIT?

Speed Limit: It’s a Problem

Transportation Research Board

2006 Annual Meeting

3

See this Example Design Speed = Operating Speed = 85% Speed (as of December 2005)

On the TANGENT:

•Passenger Cars: 144 km/h in the driving middle lane (3.50m) –VIOLATION 24 km/h

•SU Trucks: 89 km/h in the driving middle lane

•Truck-Trailers: 87 km/h in the driving middle lane

•Buses: 98 km/h

Corinth-Athens Freeway, St.:57+550

Speed Limits (km/h):

120 for PCs, 80 for SU Trucks, 70 for Truck-Trailers, 90 for Buses

General Speed Limits:

The easy part

Vehicle Type FREEWAYS High speed

roads Other rural roads

Passenger cars 130 110 90

Buses 100 90 80

Articulated Buses 70 70 70

School Buses 80 80 60

Trucks ≤ 3500 kgr 100 90 80

Trucks > 3500 kgr 85 80 80

Semi Trailer Truck≤ 3500 kgr 80 80 70

Semi Trailer Truck> 3500 kgr 80 70 70

Motorcyclists ≥ 125 cc 130 110 90

Motorcyclists < 125 cc 80 80 70

Vehicle Type FREEWAYS

Freeways – wet pavement 110

High speed roads – wet pavement 90

Other road network – wet pavement 80

Freeways / High speed roads - Bridges 100

Freeways / High speed roads - Tunnels 100

Local Speed Limits

The difficult part

King of the Road

It’s always the Driver!

By The Book

• Driver selects his/her safe speed accordingly

• Speed Limit is set only when driver can not perceive the

safe speed (obscured road, sudden pedestrian traffic,

pavement deterioration etc.)

• Speed Limit the last measure for road engineering

• CONDITIONAL and EXCUSED Speed Limit

Who Decides?

• Engineering Study

• Technical Team consisted by

– The Road Director,

– Local Police,

– Technical Chamber of Greece

• Primary Reference: OPERATING SPEED (V85)

• Use of Advisory Speed especially on Ramps for Heavy

Traffic

• Every 10 years regular reconsideration if not enforced by

accident history of specific site

Parameters?

• Grade (Speed Differential / Variance)

• Sharp curvature

• Sight Distance

• At-Grade Intersection (generally 70 km/h)

• Presence of Vulnerable road users (Children, Elderly People,

Bicyclists)

• Accident History

• Weaving Areas

• Roadside Development

• Specific Sites (Schools, Stadium, Animal Passage, etc)

For Example: Roadside

Development

MAXIMUM SPEED

LIMIT (KM/H)

Distance between Accesses (m)

Rural &

suburban

roads

Urban

roads

(Throug

h roads)

70 350 -

60 300 -

50 ≤250 ≤250

≤50 ≤200 ≤200

For Example: Through Traffic

at Freeways

Roadway Functional Classification

CROSS

SECTION

TYPE

Speed Limit

(km/h)

Rural Freeways /High Speed Highways divided

undivided

130 120 110

100 90

Rural Roads between regions /counties divided 110 100

Rural Roads between cities/towns divided 100 90

Urban Freeway / Urban divided 90 80

For Example: Weaving Sections

at Interchanges

Weaving Type Weaving

Length [m] Area Comments

Speed

Limit

[km/h] ̀

200

Rural

&

Urban

Cloverleaf

interchange

type

100

180 80

250

Rural

&

Urban between two

interchanges

100

200 80

180 Urban 60

For Example: Interchange

Ramps with max Cross-Slope 6%

Inner

Curve

Radius (m) 35 35 115 170 250 (340)

Speed

Limit

(km/h) 30 40 50 60 70 (80)

More Advisory Speeds

• Advice drivers on probable dangerous conditions when exceeding the

advisory speed limit like

• Intersections with restricted visibility

• Narrow Bridges or One-Lane Bridges

• Downgrades greater than 6%

• Ramps especially for Heavy Vehicles

• On Crest and Sag Vertical Curves

• It can be the operating speed or safe speed

• Accompanied with explaining sign

Conclusions

• A modern guide to help agencies set reliable speed limits that will be

obeyed

• Less necessity for enforcement

• Better acceptance by the driving population