PIARC International Road Safety Safety Seminar Seminar PIARC International Road Beijing 18 – – 20 20 October October 2005 2005 Beijing 18 Unsafe & safe road way design Unsafe & safe road way design for urban roads for urban roads Hans-Joachim Vollpracht Piarc TC 3.1 Chairman 2005- -10 10- -16 16 1 2005 1
Main objective objective of urban of urban Main planning & & development development planning � The reduction of the motorized traffic as far as The reduction of the motorized traffic as far as � possible e.g. by: possible e.g. by: - separating the through traffic from local traffic, separating the through traffic from local traffic, - - a good offer of public transport, a good offer of public transport, - - parking restrictions, parking restrictions, - - pedestrian zones and pedestrian zones and - - a network of biking routes. a network of biking routes. - � But urban road design remains a challenge for But urban road design remains a challenge for � urban developers and road engineers to create safe urban developers and road engineers to create safe solutions in situations which are characterized by: solutions in situations which are characterized by: 2005- -10 10- -16 16 2 2005 2
General chalange chalange of of General urban road road design design urban � Mixed composition of traffic with vehicles, Mixed composition of traffic with vehicles, � trucks, busses, motorcycles and most trucks, busses, motorcycles and most vulnerable users like pedestrians and vulnerable users like pedestrians and bicyclists bicyclists � A A variety of different functions like variety of different functions like � connection, distribution, access and connection, distribution, access and stopover stopover � Different Different activities on the roads like public activities on the roads like public � and private transport of goods and people, and private transport of goods and people, shopping, road business, parking and shopping, road business, parking and loading, children’ ’s playground etc s playground etc loading, children 2005- -10 10- -16 16 3 2005 3
Differences to interurban roads Differences to interurban roads Urban main road Three lane-interurban express Road With mixed traffic With separation of traffic And mixed functions, And only one function: Connection, Distribution Connection and Access how to improve? 2005- -10 10- -16 16 4 2005 4
Principles for Urban Road Design Principles for Urban Road Design � Different use and functions within the urban road network need different and unmistakeable design and measures for road safety � Different compositions of traffic (e.g. High traffic volume of goods or public transport) need different solutions � No dynamic design for urban roads! Through roads and urban roads must only fulfil the geometrical needs of vehicles, cyclists and pedestrians (Geometric Design). 2005- -10 10- -16 16 5 2005 5
Design different roads for different types 2 4 6 6 and functions. Four types of urban roads 50 -16 16 10- 10 -10 2005- 2005 1 3
Design and speed: Design and speed: Speed is the m ain problem for vulnerable road vulnerable road Speed is the m ain problem for users: pedestrians and cyclists users: pedestrians and cyclists In the case of a collisions with cars they survive up to 30 km/h ! In the case of a collisions with cars they survive up to 30 km/h ! Stopping sight distance Stopping sight distance has to be short in has to be short in residential areas residential areas 2005- -10 10- -16 16 7 2005 7
The faster we drive the farer we focus ahead Reverse conclusion…. Speed-related focus (point of fixation): 100km/h = 600m 65km/h = 350m 100 km/h 600m 80 km/h 500m 400m 65 km/h 300m 200m 300m 300m 100m 300m 0m The farer we look ahead the faster we drive and the smaller is our angle of view 2005- -10 10- -16 16 8 2005 8 Roth 1973 in: Cohen 1984
The farer the focus, the faster the speed! The farer the focus, the faster the speed! Rural road: small field of Urban road: far point of view. Drivers can’t see the fixation. Drivers increase intersection. speed. ! B 109/140 Groß-Schönebeck-Gollin / Mühlenstraße Berlin 2005- -10 10- -16 16 9 2005 9
Design roads as an arrangement of urban rooms (spatial sectors, places etc!) 1 2 2 3 4 Arrange- ment of spatial sectors ....tokeep speed down 2005- -10 10- -16 16 10 2005 10 10 OD-Guideline for urban roads / Germany 2002
Unsafe Cross sections sections for for urban urban Unsafe Cross situatations ( (dynamic dynamic design design) ) situatations Lane width is 3.50m, focus is far away, speed about 80 km/h and Crossing bridges for pedestrians are not accepted 2005- -10 10- -16 16 11 2005 11
W idth of carriagew ays and lanes ( geom etric design) for a speed of 50 km/h 2005- -10 10- -16 16 12 2005 12
Geom etric Design of the cross sections And Vehicle Capacity The vehicle capacity depends primarily on the design of the junctions and secondly on the number of lanes of the carriageway but not on their width! The capacity can be: 2-lane carriageway � 1400 -2200 veh/h Standard with of carriageway = 6,50 m Low volume of bus and goods traffic = 6,00 m Extreme high volume of Busses and trucks = 7,00 m 4-lane carriageway � 1800 - 2600 veh/h Standards lane width is 3,00 – 3,25 m 2005- -10 10- -16 16 13 2005 13
4 -lane carriage w ay 4-lane carriageway with median stripe: 6,50 m 2 m 6,50 m - Safe solution for 15,00 m crossing pedestrians 4-lane carriageway (without median stripe) 5,50 m 5,50 m 11.00 m 2005- -10 10- -16 16 14 2005 14
4 -lane carriage w ay with median stripe Example from Berlin Measures for safe pedestrian crossing Pedestrian traffic signal Barrier for pedestrian crossing in junction area 2005- -10 10- -16 16 15 2005 15
Urban I ntersections I ntersections have have to to be be .... .... Urban ...... visible, clear, recogniseable & walk able) 2005- -10 10- -16 16 16 2005 16
Roundabouts are the safest urban Roundabouts are the safest urban intersections on one level intersections on one level - Pedestrian way -Cariage way -Plaster ring -Pedestrian crossing outboard-ring (B) : inboard-ring (paving) 2,5 : 1 Example: B= 6,5m in- board-ring 2,00m 2005- -10 10- -16 16 17 2005 17
The entrance entrance into into round round abouts abouts is.... is.... The ...radial to the centre with Not tangential with high speed low speed into the circling traffic! 2005- -10 10- -16 16 18 2005 18
19 19 pedestrian W idth of facilities -16 16 10- -10 2005- 2005
20 20 Separation of transport modes Width of cyclist facilities -16 16 10- -10 2005- 2005
2 -lane carriage w ay Variation: 2-lane with cyclist facility Recommended by GDV (research institute of the German assurance federation) Quelle GDV 2005- -10 10- -16 16 21 2005 21
2 -lane carriage w ay Variation: 2-lane with cyclist facility Safe solution for pedestrian and cyclists Recommended by GDV (research institute of the German assurance federation) Quelle GDV 2005- -10 10- -16 16 22 2005 22
Excelent Chinese solutions Chinese solutions Excelent 2005- -10 10- -16 16 23 2005 23
Separation of transport modes Width of public transport stop facilities 2005- -10 10- -16 16 24 2005 24
25 25 W idth of public transport stop Crossing aid facilities -16 16 10- -10 2005- 2005
Lanes for Buses and delivery Lanes for Buses and delivery Parking in an extra w ide m edian stripe and “bus-lane” Example from Berlin source: “Straßen und Plätze neu gestalten” Kirschbaum Verlag 2005- -10 10- -16 16 26 2005 26
Separation of public transport Median stripe for tram-line tram mixed use of the right lane, Bus lane in rush hour, other time parking 2005- -10 10- -16 16 27 2005 27
Traffic calming measures to support speed limits and to ease the crossing of pedestrians Traffic island in section w ith high frequency of crossing pedestrians - No m edian strip in section w ith parking, good sight w ith cyclist lane - Calm ed speed level 2005- -10 10- -16 16 (Source: German insurances) 28 2005 28
2 -lane carriage w ay Variation: 2-lane with median strip - much safer solution for pedestrians, in areas with high volume of crossing pedestrians Recommended by GDV (research institute of the German assurance federation) Example with and without cyclist facility Quelle GDV 2005- -10 10- -16 16 29 2005 29
2 -lane carriagew ay Variation: 2-lane with median strip Left: before - accidents in 2 years without median strip Right: after - accidents with median strip or traffic island Pedestrian Quelle GDV 2005- -10 10- -16 16 30 2005 30
„sustainable enforcement „ by road design) 50 50 50 Use transition measures to support speed limits when entering build up areas 2005- -10 10- -16 16 31 2005 31
Measures to support speed limits Traffic islands 2005- -10 10- -16 16 32 2005 32
33 limits: Traffic calming with… 33 Measures to support speed ..... humps and bumps -16 16 10- -10 2005- 2005
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