21-Presn-Calming Measures Pedestrians Svensson

The urgent need for traffic calming measures for pedestrians in India

Åse SvenssonPhD Traffic Engineering

Lund University / LTH / Transport and Roads / Åse Svensson

Traffic safety is a problem for the society

• Each year about 1.3 million people die in road crashes and an additional 20 and 50 million sustain injuries

• Today – road crashes is the 5th leading cause of death. By 2020 – 3rd place!

• Traffic safety improves in high-income countries while it continuously becomes worse in other parts of the world

• (WHO, 2009)


Trends in high income-countries


India


Pedestrians are at stake

• 50% of all road traffic fatalities in the world are among vulnerable road users

• Higher percentage in low-middle-income countries • While in high income countries car travellers are at stake

• Vehicle speed is the key risk factor for injuries among pedestrians and cyclists (WHO, 2009)


The project• Partners: CUTS Centre for Consumer Action, Research &

Training (CUTS CART) and Lund University, Transport and Roads, Sweden

• Consultant partner: Indian Institute of Technology (IIT) Delhi

• Finance: Swedish International Development Cooperation Agency (SIDA)

• Studies in the city of Jaipur, India


Aim

• Aim of the project – to identify feasible traffic calming measures for pedestrians in Jaipur and to more generally get across an understanding for the urgent need of these in India


Method

• Extensive studies in 7 of our studied 24 intersections• Traffic flow measurements• Studies of crossing and interaction behaviour• Conflict studies• Speed measurements


Results – behaviour & intersection design• Unorganized and non-channelized

crossing behaviour• Vehicle drivers neglect crossing

pedestrians• Intersection area too spacious –

- difficult to get an overview - pedestrian crossings outside the intersection- due to poor accessibility pedestrians cross in the middle of the intersection – most conflicts occur here as well

• Barriers in form of high medians with bushes – pedestrians have to climb

• No waiting areas for bus passengers


Results – speeds for vehicles approaching the intersection

Site Car speeds MC speeds Mean 85perc Mean 85perc 1 43 52 41 50 2 42 50 42 48 3 45 54 43 51 4 45 54 44 52 5 41 50 39 46 6 40 50 41 48 7*


Vehicle speed a key-factor for safety

Strong relationship between vehicle speed and safety:1) relationship between speed and the occurrence of accidents – i.e. higher speed means less time margins to avoid a collision2) IF there is a collision then there is a relationship between speed, collision speed and injury severity


The power model

Example: Reduction of mean speed from 60 km/h (37mph) to 55 km/h (34 mph) i.e. by 8% reduces fatal accidents by 25-35%.

Source: Nilsson, 2004


Source: Davis (2001)

Probability of pedestrian fatality for different age groups at different collision speeds


Speeds will have to be reduced – but how?

• According to traffic safety research humps and raised pedestrian crossings would be feasible and low cost measures to reduce vehicle speeds and thereby reduce pedestrian injury accidents


• Low costs• Humps entrances• Raised pedestrian crossings

at exits• Raised footpaths at corners• Medians (with passage) and

pedestrian crossings are moved closer to the intersection

Proposed Standardised Traffic Calmed intersections

Hump – 3,6 m wide, circular top, 10 cm high at its peak, located 10-14 m in advance of the pedestrian crossing.

Raised area for pedestrians

Zebra crossingRaised Zebra crossing -Flat top, 5 m wide, 10 cm high, 1 m ramp

Traffic Calmed Standardised T- and Four Arm Intersection


The Watts hump is circular-shaped and reduces speed to appr. 30km/h


Raised pedestrian crossing with similar effect as the hump


Effects on accidents of speed-reducing devices according to meta-analysis by Elvik (2009).

• At humps injury accidents are reduced by 41% (-57;-34)• Raised pedestrian crossings vs ordinary pedestrian

crossing reduce pedestrian injury accidents by 42% (-70;+11)


Would these measures work in Jaipur?

• As decisions regarding implementations were not made in time – expected behaviour had to be estimated by comparing similar types of humps in Jaipur and in Sweden

• AND the speed reducing behaviours were very similar• Indications that humps in India preferably could be shorter

than in Sweden but the correct height to length relation will of course have to be tested out.

• At humps in Jaipur, MC speeds were on average 4 km/h (2,5mph) higher than car speeds.

• Speed breakers – “too efficient”


Conclusions

• Speed as the key factor for pedestrian safety is universal• The correct measures have to be adapted to the prevailing

traffic conditions• The proposed measures slow down traffic both when entering

and exiting the intersections• Improve safety and accessibility by locating pedestrian

crossings so they become attractive to use for pedestrians • All-in-all – A large scale implementation of the Proposed

Standardised Traffic Calmed Intersections has the requirements of improving safety, accessibility and quality of life for all pedestrians


References• Anderson R.W.G., McLean A.J., Farmer M.J.B., Lee B.H., Brooks C.G.; Vehicle travel speeds and incidence

of fatal pedestrian crashes. AA&P, Vol 29, No 5, pp 667-674, 1997.• Davis, G. (2001) “Relating severity of pedestrian injury to impact speed in vehicle-pedestrian crashes”,

Transportation Research Records: Journal of the Transportation research Board, Volume 1773 / 2001, pp. 108-113

• Elvik, R., Christensen, P., Amundsen, A. (2004) “Speed and road accidents – An evaluation of the Power Model”, TØI report 740/2004, Oslo

• Elvik, R., Erke, A., Sørensen and Vaa, T. (2009) “Handbook of Road Safety Measures”, TØI, Oslo• Gudjonsson, H. (2011) Samband mellan skadeutfall hos påkörda oskyddade trafikanter och hastighetsnivå på

olycksplatsen. Presentation på Transportforum, Linköping, 2011-01-12.• Hydén, C. (1987). The development of a method for traffic safety evaluation: the Swedish traffic conflict

technique, Bulletin 70, Department of Traffic Planning and Engineering, Lund University, Lund• Hydén, C., Svensson, Å. (2009) “Traffic Calming in India – Report on the theory of Traffic Calming and

empirical trials in the city of Jaipur”, Bulletin 252, Lund Institute of Technology, Department of Technology and Society, Traffic and Roads, Lund

• Nilsson, G. (2004) “Traffic safety dimensions and the Power Model to describe the effect of speed on safety”, Bulletin 221, Lund Institute of Technology, Department of Technology and Society, Traffic Engineering, Lund

• WHO (2009) “Global status report on road safety: time for action”. Geneva, World Health Organization, 2009 (www.who.int/violence_injury_prevention/road_safety_status/2009).


Thank you!

Åse [email protected]

mailto:[email protected]

http://www.tft.lth.se/


Percentage change in the number of accidents

Accident severity Types of accidents affected Best

estimate

95% confidence

interval Speed humps

Injury accidents All accidents on roads with speed humps -41 (-57; -34)

Injury accidents All accidents on roads nearby roads with speed humps -7 (-14; -0)

Raised junctions Injury accidents Accidents at junctions +5 (-34; +68)

Rumble strips in front of junctions Injury accidents Accidents at junctions -33 (-40; -25)

Speed zones Injury accidents All accidents -27 (-30; -24)

Effects on accidents of speed-reducing devices according to metaanalysis by Elvik (2009).

Source: Elvik et al. (2009)


Percentage change in the number of accidents

Accident severity Types of accidents affected Best

estimate

95% confidence

interval Marked crosswalk

Injury accidents Pedestrian accidents, two-lane roads -8 (-43; +51) Injury accidents Pedestrian accidents, multi-lane roads +88 (-32; +424) Injury accidents Pedestrian accidents, all roads +44 (-6; +121)

Raised crosswalk vs. no crosswalk Injury accidents All accidents -65 (-83; -27)

Raised crosswalk vs. ordinary marked crosswalk Injury accidents Pedestrian accidents -42 (-70; +11)

Refuge in marked crosswalk vs. ordinary marked crosswalk Injury accidents Pedestrian accidents -43 (-71; +12)

Effects on accidents of traffic control measures for pedestrians

Source: Elvik et al. (2009)


Pedestrian injury in relation to pedestrian age and mean speed at the site

Source: Gudjonsson (2011)

21-Presn-Calming Measures Pedestrians Svensson

Documents

Transcript of 21-Presn-Calming Measures Pedestrians Svensson