A Canadian study finds poorly designed urban streets contribute to childhood injury. (Associated Press)

Improving how Canadian roads and walkways are designed and built could reduce the number of children injured or killed each year, a new report suggests.

Injury is the leading cause of death among children in North America, many of them traffic-related injuries that can be traced back to poor community design decisions, like locating a school on the wrong side of a busy street, says Dr. Andrew Howard in a paper published in the Canadian Medical Association Journal.

"Nobody sat down and said let's make it so that children are run over by cars. Nobody sits down to design this," Howard said in an interview with cbc.ca.

As an orthopedic surgeon at Toronto's Hospital for Sick Children, he's seen "the sort of severe and preventable tragedies that have to do with road traffic or sports and leisure injuries."

Howard set out to look at pedestrian injuries because so much injury investigation in the past has focused on children inside the car, rather than those outside the car.

Injury accounts for about 40 per cent of childhood deaths in industrialized countries. The report says 371,000 boys and 289,000 girls worldwide died of injuries in 2002 — including more than 180,000 killed in traffic accidents, mainly as pedestrians.

"'Slow' is the magic bullet for urban traffic," said Howard. "But drivers become very nervous when you slow them down."

A child who is hit by a car going 30 km/h is much more likely to survive compared to one hit by a car going 50 km/h, he said.

What else can slow down traffic? Opening up a street to two-way traffic versus one-way traffic is a start. And like many auto-myths, it is counterintuitive, he said. Most people would guess a one-way street is safer for pedestrians, but actually the cars go faster.

As he looked from country to country, Howard noted that new North American communities are still fairly "car-centric," which is quite different from European cities and towns, where planning is around people who walk, public transit users and cyclists.

In Canada, he said, there are about 10 injury deaths per 100,000 children per year, adding up to about 500 deaths.

"And if you look at Sweden, which has just as much snow and just as much northness and just as much distance between towns, a lot of rural dwellers, some cities, very similar, but (they have) about five deaths per 100,000 per year. Really half the rate."

So what can be learned from Sweden?

One example he cited is suburban arterial roadways that send the cars to underground roundabouts at intersections, allowing pedestrians to walk along their route at ground level.

"You don't build a bridge and make the sidewalk go up because people don't like to climb across a road and will skip across the road, and then you have to put up a fence to stop them," Howard explained.

Not only are pedestrians safer, but the design does away with side-impact car crashes, which Howard said are responsible for 40 per cent of the deaths and bad neurological injuries for Canadian children.

"It's an expensive intersection to build," he observed. "It's a luxury intersection, right? And here the way that our incentives are written ... we almost direct our tax dollars toward luxury cars rather than towards luxury intersections."

The secondary problem of children not being safe on urban and suburban streets is that they are spending more time inside being sedentary, said Howard.

"We're raising a generation of kids who have never ever ridden their bicycles to school, where if you walk to school you're in the minority," said Howard.

With files from The Canadian Press