Urban Traffic Calming

Transcription

1 Motorized Traffic and Health: Implementing Interventions to Mitigate Impacts Urban Traffic Calming Olivier Bellefleur François Gagnon CPHA, Edmonton June 11 th, 2012

2 Outline Traffic calming: definitions Political dimensions The literature review Health inequalities Workshop 2

3 A concept with various uses 1. Calmed new developments: e.g. Radburn, N.J. 3 Source: Wikimedia Author: Fgrammen

4 A concept with various uses Retrofitting of existing street networks through 2. discrete measures 3. systemic measures 4

5 Source: Photographer: Dan Burden. Source: Photographer: Dan Burden. Source: Photographer: Dan Burden. Our working definition of traffic calming Interventions on street networks that involve the installation of various measures in order to reduce speed or volumes of motorized vehicles according to one of two broad approaches: Black-spots Area-wide 5

6 Source: Department for Transport, 1999, p.2. Source: City of Edmonton, 2008, p. 29. Our working definition of traffic calming Interventions on street networks that involve the installation of various measures in order to reduce speed or volumes of motorized vehicles according to one of two approaches: Black-spots Area-wide 6

7 Source: Department for Transport, 1999, p.2. Source: City of Edmonton, 2008, p. 29. Political dimensions Part of strategy to mitigate impacts of more car-km tions.ccnpps?id_article=670 Part of a strategy to reduce car-km 7

8 Political dimensions Municipal denormalization of 50km/hr speed limit on residential streets State codifications of reduced speeds and new hierarchies of uses of residential streets Source: Department for Transport, 1999, p.2. 8

9 What are the effects of these two approaches? Our literature review: Methodology Logic model Results 9

10 Source: Photographer: P:B!rch. Source: Photographer: InfoCog. Source: Photographer: beefy_n1. Source: Photographer: Velovotee. Methodology 1. Systematic search of peer-reviewed (n=19) and grey literature (n=10) for evaluative studies of urban traffic-calming interventions on four determinants of health: Collisions Air quality Noise Active transportation 10

11 Source: Abbott et al., 1995, p. 9. Methodology 2. A broader search for peer-reviewed (n=36) and grey literature (n=38) to identify: research gaps methodological issues mechanisms of action 3. A comparison of the black-spots and the area-wide appoaches 11 E.g., The relationship between speed and noise

12 Logic model TRAFFIC-CALMING POLICY Black-spots approach Area-wide approach PRINCIPAL MECHANISMS OF ACTION Reduction of speeds Reduction of volumes EFFECTS ON HEALTH DETERMINANTS Reduction of the number and severity of collisions Improvement of air quality Reduction of environmental noise Increase in active transportation 12

13 Source: Photographer: WSDOT Results: Collisions Black-spots and area-wide: substantial reductions in the number and severity of collisions for all users of the streets (drivers, cyclists, pedestrians, children, etc.). Single-lane roundabout: -77% injury collisions (Retting et al., 2001) Source: Grundy et al., 2009, p mph (32-km/h) zones in London: -42% injury collisions (-49% children) (Grundy et al., 2009) 13

14 Effectiveness and scale Pedestrian black spots* ( ) Sites where 8 or more pedestrians were injured (37) Road network *Victim of a road crash that resulted in an intervention by Urgences-santé Projection: NAD83, MTM zone 8 Sources: City of Montréal, Urgences-santé Cartographic prod.: MS Cloutier, 2004 Direction de santé publique de Montréal (Adapted from Morency & Drouin, 2008) (Adapted from Morency & Drouin, 2008) 14

15 Source: Photographer: Dan Burden. Results: Air quality Black-spots and area-wide: increase in per vehicle emissions (CO 2, VOC, CO, NO X, PM), for most interventions (speed reduction & speed variations). Area-wide: can reduce overall emissions (volume reduction). An exception: Replacing stop sings with a mini-roundabout Ambient air quality: little or no effect. 15

16 Results: Noise Cars: noise reduction, for most interventions (speed reduction). Heavy vehicles: noise increase, for most interventions (speed variations and/or vertical deflections). Source: Photographer: Dan Burden. Vertical deflections: residential streets heavy vehicles 16

17 Source: Photographer: Greg Raisman. Results: Active transportation Perceived road safety: amelioration for pedestrians, parents, and drivers. Cyclists: concerned about horizontal deflections and narrowings forcing them closer to moving vehicles. Number of active trips: uncertain effects. A narrowing adapted for cyclists Physical activity: uncertain effects. 17

18 Summary Intervention logic: Evidence: All street users TRAFFIC-CALMING POLICY Black-spots approach Area-wide approach PRINCIPAL MECHANISMS OF ACTION Reduction of speeds Reduction of volumes EFFECTS ON HEALTH DETERMINANTS Reduction of the number and severity of collisions Improvement of air quality Reduction of environmental noise Increase in active transportation Per vehicle emissions Total emission, with traffic volume reductions Little or no effect on air quality Cars Most promising intervention: Area wide Reduces speeds Reduces speed variations Reduces traffic volume Reduces health inequalities Trucks Perceived safety (most users) # of active trips and physical activity 18

19 Transportation and inequalities Inequalities between who and who? Socio-economic status (SES) Income Racial traits Place of residence Mode of transportation Inequalities of what? Age Gender Accessibility Collisions, injuries, fatalities Air quality Noise Perceived safety (motorists, cyclists, children, etc.)... 19

20 E.g. Collision-related injuries by Socio-Economic Status group (SES) CIHI, 2008, p

21 E.g. Noisy or polluted neighbourhoods by income CIHI, 2011, p

22 Source: NCCHPP. Photographer: François Gagnon. Source: NCCHPP. Photographer: François Gagnon. Explanations? Traffic volume Traffic speed Street designs Grid pattern Etc.

23 Average number of injuries/intersection % intersections with arterial streets or high traffic How can traffic calming reduce inequalities? Black-spots approach: Locations at high risk for collisions are often in low SES neighbourhoods. Distribution of collision-related injuries in Montréal Pedestrians Cyclists Arterial streets High traffic Promising strategy to reduce collision-related injuries (correlation to inequalities), but not evaluated Lowest Average income Highest Adapted from Morency, 2009, p

24 How can traffic calming reduce inequalities? Area-wide approach: Giving priority to low SES neighbourhoods: Collision-related injuries 2 positive evaluations Pollution (air & noise) Perceived safety Promising, but not evaluated 24

25 Prevented injuries E.g mph zones in London, U.K. % of km of street by deprivation quintile covered by 20-mph zones in Prevented injuries in Adjacent streets In 20-mph zones Least deprived Most deprived Least deprived Most deprived Source of data: Grundy et al., 2008, p.39. Source of data: Grundy et al., 2008, p

26 Child pedestrian injury rate Child pedestrian njury rate Density (n.b. traffic calming mesures/street km) E.g. Two similar cities, U.K. Distribution of traffic-calming measures by SES zones Most affluent Next affluent Next deprived Most deprived City A City B Source of data: Jones et al., 2005 City A (U.K.) City B (U.K.) (4-16 year olds; 0 /00) Most deprived Most affluent (4-16 year olds; 0 /00) Most deprived Most affluent Source of data: Jones et al., 2005 Source of data: Jones et al.,

27 Intervention logic: Unintended effects on inequalities? TRAFFIC-CALMING POLICY Black-spots approach PRINCIPAL MECHANISMS OF ACTION Reduction of speeds EFFECTS ON HEALTH DETERMINANTS Reduction of the number and severity of collisions Improvement of air quality Area-wide approach Reduction of volumes Modal transfer (to cycling, ) Traffic diversion (from one local street to another or from local streets to major roads) Reduction of environmental noise Increase in active transportation People of low SES tend to be overrepresented near major roads + Burdens from transportation are already high 27

28 A simple framework near the intervention? where some of the motorized traffic might be diverted? What are the anticipated effects of an intervention on the main determinants of health... Who lives, works, studies, etc.,... Positive effects: Negative effects: Who benefits? Who bears the burden? Traffic diversion: Yes/No? Positive effects: Negative effects: Traffic diversion: Yes/No? Who benefits? Who bears the burden? Who travels by what mode (car, cycling, walking, etc.)... Who benefits? Who bears the burden? Traffic diversion: Yes/No? Who benefits? Who bears the burden? 28

29 with a temporal dimension near the intervention? where some of the motorized traffic might be diverted? Effects over time? Traffic patterns over time? What are the anticipated effects of an intervention on the main determinants of health... Who lives, works, studies, etc.,... Positive effects: Negative effects: Who benefits? Who bears the burden? Traffic diversion: Yes/No? Positive effects: Negative effects: Traffic diversion: Yes/No? Who benefits? Who bears the burden? Mode split over time? Movement of vulnerable populations over time? Who travels by what mode (car, cycling, walking, etc.)... Who benefits? Who bears the burden? Traffic diversion: Yes/No? Who benefits? Who bears the burden? Medium term Short term Long term 29

30 References Abbott, P., Tyler, J., & Layfield, R. (1995). Traffic calming: vehicle noise emissions alongside speed control cushions and road humps (Report No. TRL 180). Crowthorne, Berkshire: Transport Research Laboratory. Bellefleur, O. & Gagnon, F. (2011). Urban Traffic Calming and Health: A Literature Review. Montréal: National Collaborating Centre for Healthy Public Policy. Retrieved from: Canadian Institute for Health Information. (2008). Reducing Gaps in Health: A Focus on Socio-Economic Status in Urban Canada. Ottawa: CIHI. Retrieved from: Canadian Institute for Health Information. (2011). Urban Physical Environments and Health Inequalities. Ottawa: CIHI. Retrieved from: Department for Transport. (1999). Leigh Park Area Safety Scheme, Havant, Hampshire (Report No. Traffic Advisory Leaflet 2/99). London: TSO. Retrieved from: %20Hampshire.pdf Edmonton, the City of. (2008). Motor Vehicle Collisions Edmonton. Retrieved from: Gagnon, F. & Bellefleur, O. (2011a). Traffic Calming: An Equivocal Concept. Montréal: National Collaborating Centre for Healthy Public Policy. Retrieved from: Gagnon, F. & Bellefleur, O. (2011b). Traffic Calming: Political Dimensions. Montréal: National Collaborating Centre for Healthy Public Policy. Retrieved from: Grundy, C., Steinbach, R., Edwards, P., Green, J., Armstrong, B., & Wilkinson, P. (2009). Effect of 20 mph traffic speed zones on road injuries in London, : controlled interrupted time series analysis. BMJ, 339, b4469. doi: /bmj.b4469 Grundy, C., Steinbach, R., Edwards, P., Wilkinson, P., & Green, J. (2008). The Effect of 20 mph zones on Inequalities in Road Casualties in London: A report to the London Road Safety Unit. London: London School of Hygiene and Tropical Medicine. Retrieved from: Jones, S. J., Lyons, R. A., John, A., & Palmer, S. R. (2005). Traffic calming policy can reduce inequalities in child pedestrian injuries: database study. Injury Prevention, 11, doi: /ip Morency, P. (2009). Blessés de la route, des inégalités qui s expliquent. Développement social, 10(2), 31. Morency, P. & Drouin, L. (2008). Traffic Calming. Evidence for Action. Presentation at the workshop Evidence and policy making at Journées annuelles de santé publique. Retrieved from: Retting, R. A., Bhagwant, P. N., Garder, P. E., & Lord, D. (2001). Crash and Injury Reduction Following Installation of Roundabouts in the United States. American Journal of Public Health, 91(4),

31 Thanks! Olivier Bellefleur , ext François Gagnon , ext Our documents are available in French and English online at: 31