DAVID STAPLES,
If city council is going to make sound decisions, it needs solid information from city administration. It’s not yet getting that in the debate on whether to lower residential neighbourhood speed limits.
City officials have made exaggerated claims about the unreasonable stubbornness of those who oppose lowering the speed limit and about the overall carnage caused by speeding. Our residential streets have been made out to be much more deadly than they actually are.
It’s also being suggested that lowering the speed limit to 30 km/ h will have much more of an impact than it likely will.
Both council and citizens appear to be deeply divided on lowering speed limits, with a strong suburbs-versus-mature neighbourhood split. One major fracture centres around the city’s botched attempt to gauge public support for dropping speed limits.
As I mentioned in a previous column, the city surveyed 676 citizens, with folks asked if they support a 30 km/ h limit. There was little support for this.
Folks were then asked the same question a second time, but only after they had been shown a “survivability graphic” that says eight out of 10 pedestrians will die if they get hit by a car going 50 km/ h, four out of 10 will die if the car is at 40 km/ h, but just one out of 10 will die if the car is going 30 km/h.
It turns out, however, that those survivability rates are based on studies from the early 1980s that greatly over-estimate the number of fatal accidents at various speeds.
The city’s source was a 2008 report by the World Health Organization, which links this data to another report, which links to the ultimate source, a 1983 study from Sweden. But more recent studies spell out major flaws in the 45-year-old Swedish study and others like it.
“Without exceptions, papers written before 2000 were based on direct analyses of data that had a large bias toward severe and fatal injuries,” writes a Danish researcher in a 2011 survey of such studies. “The consequence was to overestimate the fatality risks. We also found more recent research based on less biased data or adjusted for bias. While still showing a steep increase of risk with impact speed, these later papers provided substantially lower risk estimates than had been previously reported.”
For example, the city says the survivability rate of collision between a pedestrian and a car going 40 km/h is six in 10. But a 2011 study by the American Automobile Association’s Foundation for Traffic Safety found the survivability rate for such a 40 km/ h collision is nine in 10.
When it comes to pedestrians and collisions, there’s a dividing line at 40 km/ h, a French study from 2017 found: “For speeds less than 40 km/ h, because data representative of all crashes resulting in injury were used, the estimated risk of death was fairly low.”
I pointed out these newer studies to Gerry Shimko, executive director of Edmonton’s traffic safety department. He said he’d look into them, but said no study can claim to be definitive: “I’d say there’s no consistency in terms of those studies.”
Even after the city shared its incorrect survivability data with the public, only 38 per cent voted for the 30 km/ h low limit on local residential roads.
It could well be that neither the public nor the facts support a drop to 30 km/ h.
The city’s survey was also attacked at Tuesday’s council meeting because it wasn’t a scientific sample, so it didn’t fairly represent the views of the general public.
The city’s report also characterized the sizable minority of Edmontonians against any change to speed limits as universally against all efforts by the city to make our streets safer.
When challenged on this blackand-white characterization, Ian Large of the Leger polling firm, which helped write the city report, said: “Well, I appreciate there may be a little hyperbole in the statement ...”
Ward 9 Coun. Tim Cartmell shot back: “I’m a little concerned that we have a report that you’ve just said contains some hyperbole that we’re depending upon to make decisions.”
Cartmell and council voted Tuesday to gather more information, such as on injury rates on our residential streets, before making any decision. This is a good place to start, or at least it will be if the information that administration provides is clear, unbiased and up to date.
A compromise of 40 km/ h on local roads, with greatly reducedin-size 30 km/ h playground and school zones, looks like it might get widespread acceptance, but only if we can make decisions based on facts.