Safety in Numbers Peter Jacobsen, Engineer Towards Carfree Cities VIII: Rethinking Mobility, Rediscovering Proximity June 17, 2008

What is Safety? Well padded?

Well padded?

What is Safety? No injuries? No danger? No fear?

No injuries?

No danger?

No fear?

Injuries

Injuries per Capita 2.8x

Amount of Walking 10x

Injury Risk per Walker 3x

Safety in Numbers

Walking in 68 California Cities

Bicycling in 68 California Cities

Overall Injury Rate in 68 California Cities

Pedestrians at Intersections in Oakland Bicyclists at 95 intersections in Malmö, Sweden Bicyclists at 45 bike path intersections in Gothenburg, Sweden Pedestrians at 300 intersections in Hamilton, Ontario

Walking and Bicycling in 47 Danish Towns Distance Bicycled in 14 European Countries Walking and Bicycling Trips in 8 European Counties Walking and Bicycling in 68 California Cities

Bicycling in United Kingdom and The Netherlands

Key Points Safety-in-Numbers Safer where more people walk or bicycle Consistent, replicable, plausible, dose-response relationship Tripling walking or bicycling: Halves individual risk Increases total injuries by only 50% Comparisons difficult

Safety-in-Numbers

Safer where more people walk or bicycle

Consistent, replicable, plausible, dose-response relationship

Tripling walking or bicycling:

Halves individual risk

Increases total injuries by only 50%

Comparisons difficult

Why? What or who changes? Pedestrians and bicyclists? Motorists? Trauma care? Roadway design? Laws?

Pedestrians and bicyclists?

Motorists?

Trauma care?

Roadway design?

Laws?

Lessons Get more walking and bicycling Make the streets comfortable Mark crosswalks Designate bike lanes Extend curbs and raise medians at intersections Lower motorists’ speeds Cut travel time (reduce delays)

Get more walking and bicycling

Make the streets comfortable

Mark crosswalks

Designate bike lanes

Extend curbs and raise medians at intersections

Lower motorists’ speeds

Cut travel time (reduce delays)

What is Safety? No injuries? No fear?

No injuries?

No fear?

Peter Jacobsen [email_address] Safety-in-Numbers paper: Injury Prevention 2003; 9 :205 – 209 http://tinyurl.com/23g95j

Extra Slides Not Used

Better Medicine

Scientific Method Plausibility Consistency Strength Specificity Temporality Dose-response relationship Coherence Experimental evidence Analogy

Plausibility

Consistency

Strength

Specificity

Temporality

Dose-response relationship

Coherence

Experimental evidence

Analogy

Consistent Relationship

THE VOLUME – RISK RELATIONSHIP As the number of pedestrians goes up, the number of collisions per pedestrian (risk) drops exponentially

As the number of pedestrians goes up, the number of collisions per

pedestrian (risk) drops exponentially

Step 6: Identify Areas of High Pedestrian Risk Create Pedestrian Risk Index based on exposure and vehicle collisions. Annual pedestrian vehicle collisions Average annual pedestrian volume Used to generate a list of Oakland’s “Dirty Dozen”, or 12 most dangerous intersections. 10 of the 12 most dangerous intersections were found in areas of low pedestrian volume. The highest volume streets were found to be among the safest. OAKLAND PEDESTRIAN EXPOSURE MODEL = Relative Pedestrian Risk

Create Pedestrian Risk Index based on exposure

and vehicle collisions.

Annual pedestrian vehicle collisions

Average annual pedestrian volume

Used to generate a list of Oakland’s “Dirty Dozen”, or

12 most dangerous intersections.

10 of the 12 most dangerous intersections were found in areas

of low pedestrian volume. The highest volume streets were

found to be among the safest.

Intersections Pedestrians at ~300 intersections in Hamilton, Ontario (Leden) Bicyclists at 95 intersections in Malm ö , Sweden (Ekman) A threshold at 50 bicyclists per hour Bicyclists at 45 bike path intersections in Gothenburg, Sweden (Leden)

Pedestrians at ~300 intersections in Hamilton, Ontario (Leden)

Bicyclists at 95 intersections in Malm ö , Sweden (Ekman)

A threshold at 50 bicyclists per hour

Bicyclists at 45 bike path intersections in Gothenburg, Sweden (Leden)