Your Health

What's your hurry?

Lower speed limits will save lives

BY DR. LYNNE WARDA
Winnipeg Health Region
Wave, September / October 2012

Motor vehicle collisions (MVCs) are the leading killer of young Canadians. The good news is that many traffic-related deaths and injuries can be prevented by simply slowing down.

Road safety innovations, such as seatbelts, airbags, and improved vehicle design, have been credited with a steady decline in traffic fatalities over the past 40 years. Graduated drivers' licensing and measures to address impaired and distracted driving, such as texting and cell phone use, are more recent examples of issues for which effective policies and programs have been introduced. Despite these and other initiatives, traffic injuries continue to cause disability and death at an unacceptable rate.

What else can be done? Speed is one key factor that must be addressed to further reduce injuries to motor vehicle occupants, pedestrians and cyclists. Speed, more than any other factor, predicts the chance of injury and death, particularly among vulnerable road users such as pedestrians and cyclists.

In Winnipeg, the speed limit for all streets is 50 km/h, unless otherwise posted. Only a few streets have posted speeds of 30 km/h. Most people would agree that driving too fast increases the risk of a serious collision, but how fast is too fast? Consider this: A pedestrian struck by a car travelling 30 km/h has a 90 per cent chance of survival. This drops to 60 per cent at 40 km/h. Above 60 km/h, the chance of survival reduces even further.

In a 2012 Manitoba Public Insurance survey, one in five Manitobans cited "speeding" as the single greatest driving safety problem in Manitoba. When asked directly, 72 per cent of Manitobans said speeding on streets in cities and towns is a very or somewhat serious problem.

Given that Manitobans are already aware of the dangers of speeding, what additional steps can we take? Many jurisdictions worldwide have implemented initiatives to address the problem of residential traffic speed. Reducing speed limits has been one effective strategy, particularly where vehicles are in close proximity with pedestrians and cyclists. In 1986, the City of London reduced commuter traffic speeds to 20 mph (32 km/h) and found that injuries were reduced by 42 per cent. The benefits were greatest in children, with a 50 per cent reduction in deaths and serious injuries.

Other cities in Europe and Australia have had similar success. However, it is clear that drivers routinely exceed posted speed limits on roads that are designed for higher speeds when there is no active enforcement. Traffic-calming measures, such as speed bumps and other road design features, do not require enforcement and are now routinely used in conjunction with lower speed limits in neighbourhoods across Canada.

There are many other reasons to consider lowering residential speed limits. Arguably the most significant could be an increase in active transportation (walking and cycling), and all the associated health benefits that result. In addition to increased physical activity, this list includes better mental health and improved air quality.

One of the hypothesized downsides to our car-dependent culture has been a reduction in more active forms of transportation. Research has shown a significant reduction over recent decades in the percentage of children who walk or ride their bicycles to school. In the United Kingdom, some studies have shown that by reducing residential speed limits and making the streets less dangerous for pedestrians and cyclists, people are more likely to commute by foot or bicycle. For example, one research study showed that cycling in Bristol increased 12 per cent after introducing 20 mph speed zones.

Recently, the City of Winnipeg approved plans to reduce speed limits around elementary schools to 30 km/h. While new to our city, 30 km/h school zones have been around for many years in cities across Western Canada. Making this change is not without its challenges.

Studies in Saskatoon and Edmonton completed after implementing 30 km/h school zones suggested that compliance was generally low, with average driving speeds lowered only by two to three km/h. In addition to simply posting lower limits, drivers are more likely to slow down in areas where children are visible, where school or playground fences are visible, and in zones near a stop sign or traffic light. Additionally, measures such as speed bumps, prominent signage and speed display devices improve drivers' awareness and compliance.

So, why wouldn't speed limits in all residential areas be lowered? Children are at risk beyond school speed zone areas.

Drivers cite concern about increased travel times, and surveys have found that drivers often speed up if they are behind schedule. While the odds of being involved in a traffic collision on any given day are low, the reality is that 70 occur every day in Manitoba. And while the time savings of going a little faster on a short trip is usually measured in seconds, the consequences can be lifelong.

Currently, there is a motion being considered by Winnipeg City Council to introduce a 40 km/h speed limit in residential areas. The public health benefits of this motion could be significant. Simply slowing down can reduce collisions, injuries and deaths, but also can encourage more active forms of transportation and contribute to a healthier community.

Dr. Lynne Warda is Medical Director of IMPACT, the Winnipeg Health Region's injury prevention program.

	About Wave Wave is published six times a year by the Winnipeg Health Region in cooperation with the Winnipeg Free Press. It is available at newsstands, hospitals and clinics throughout Winnipeg, as well as McNally Robinson Books. Read the September / October 2012 issue of Wave