Safety in numbers

From Wikipedia, the free encyclopedia

Safety in numbers is the theory that by being part of a large physical group or mass, an individual is proportionally less likely to be the victim of a mishap, accident, or other bad event.

Examples of safety in numbers include flocks of birds and shoals of fish. In both of these instances, by being part of a large group, individuals face less risk of falling victim to predators than they would if traveling alone.

Safety in numbers is also used to describe the theory that a motorist is less likely to collide with a pedestrian or bicyclist if more people walk or bicycle. A Public Health Consultant has concluded that the theory is correct, based on statistical analysis of collision data^[1]. A Cycling Transportation Engineer has disputed that conclusion, writing that the data used is insufficient to demonstrate that there is a cause-and-effect relationship^[2].

After cycling was promoted in Finland, the number of trips increased by 72% and there was a 75% drop in cyclists deaths^[3]. Motor vehicle traffic decreased by 16%, bicycle use increased by 28% and cyclist injuries decreased by 20% after the London Congestion Charge began^[4]. While such data shows a degree of correlation, conclusions of causality may very well be based on a statistically spurious relationship.

[edit] References

1. ^ Jacobsen, P. L. (2003). Safety in numbers: more walkers and bicyclists, safer walking and bicycling. Injury Prevention 9 (3): 205-209. 
2. ^ Forester, John. Does Increasing the Number of Cyclists Reduce the Accident Rate? (html). Review of Safety in Numbers.
3. ^ Saari R. (2005). Cycling policy in Finland and relevance of CBA for the policy. In: CBA of Cycling. Copenhagen, Nordic Council of Ministers, 556.
4. ^ Transport for London (April 2005). Congestion Charging: Third Annual Monitoring Report..