SAFER ROAD DESIGNS ARE BETTER ROADS THAT LAST LONGER

Earlier this summer, Vancouver, following Victoria's actions, established a comprehensive urban speed maximum of 30km/h as part of this fast growing global trend. In all, over 60 BC municipalities have adopted a 30km/h speed limit. Ontario municipalities such as Toronto, Waterloo, and Kingston have also done so.

The Canadian Association of Road Safety Professionals have long advocated for a maximum 30km/h urban speed limit, noting that it “is internationally recognized that traffic speeds of 50km/h are sub-optimal in terms of risk to pedestrians and cyclists both through the inability to avoid crashes and the subsequent severity.“ 

The National Collaborating Centre for Healthy Pubic Policy identified that a pedestrian struck by a vehicle moving at 50km/h has a 10% chance of survival, compared to a 90% chance of survival when struck by a vehicle moving at 30km/h.

A maximum urban speed limit of 30km/h is now widely advocated “for casualty reduction, active travel encouragement, transport equality and reducing noise and pollution”.

A recent local poll showed considerable support for a reduced urban speed, even without reviewing the many co-benefits.

So beyond safety, and the prevention of collisions, death, serious injuries, and the economic costs of crashes, and to encourage active travel choices, and expand road user equity and reduce noise and pollution, what other co-benefits exist with a 30km/h?

One co-benefit directly solves a huge complaint for most drivers: road quality. A slower speed limit leads to lower road (and vehicle!) damage and repair costs, and lower property taxes that can be allocated to important community needs like our mental health and addiction challenges.

How does a slower speed improve the quality of our roads (and vehicles)? It does so by removing the single largest factor that the city can control causing road damage: momentum.

Momentum is effectively the energy imparted from a moving vehicle to the road surface and is a function of vehicle weight (mass) and speed (velocity). Cities can't control vehicle weight, but they can control speed.

Now, to be more accurate, momentum is not a form of energy. But kinetic energy is, and this is why speed is so important, because while momentum is equal to only mass X velocity (mv), the kinetic energy imparted to the road surface is actually dependent on the square of velocity (v²), which is always going to be a much bigger value (KE = 1/2mv²) than just mv.

In fact, exponentially bigger.

This makes a very strong argument to reduce speed (velocity) to preserve our roads and tax dollars, and increase road user safety.

While the city is debating about sinking $331M of our tax dollars to reproduce the roads in the same manner that causes collisions and damages our roads, it might be time for a rethink of that approach in favour of one that conserves and preserves our roads and actually enhances road user safety all at a tremendous savings.

A slower speed limit is perhaps the least expensive, most effective, fairest way the city can derive huge dividends and co-benefits.

And it can be done today, at basically zero cost. More accurately, at a tax benefit when you consider the savings to taxpayers and drivers alike, not to mention other co-benefits.

Done everywhere as the default, it eliminates the cost of hundreds of signs, and also eliminates the variable and confusing problems with velocitisation as drivers move from one speed zone to another.

A default 30km/h unless otherwise posted normalises a safe, fair, equitable, healthy speed with ripple benefits such as lower taxes and less road damage across the entire community.

Our roads are going to deteriorate a lot faster under the mass of electrification, with twice as much road deterioration. And while the city struggles to repair a dozen lane-kilometers of our 1,200 lane-kilometers of roads each year at an astronomical taxpayer expense of $331M in the next decade, every single other road will continue to deteriorate in a futile whack-a-mole game, leaving our roads (and finances and safety!) worse off in a decade, despite the huge and futile repair expenses, delays and disruptions.

Setting a human-scale urban speed limit maximum of 30km/h or slower – under a Vision Zero plan for example – that improves road user safety, reduces costs and inequities, and preserves our infrastructure is both progressive and timely.