Debates over the merits of the current speed limits have recently emerged in Ontario and British Columbia. The Stop 100 campaign is arguing that the speed limit on the 400 series highways in Ontario should be increased from 100km/h to 120km/h. Similarly, a BC group known as Safety by Education Not Speed Enforcement (SENSE) is arguing that their provinces speed limit should be increased to 140km/h.
The merits of various speed limits are certainly up for debate. After all, there is theoretically a level of speed beyond which drivers are unreasonably endangering others in various contexts. For instance, it would be ludicrous to allow motorists to drive 100km/h through a cul de sac. But determining the optimal speed limit is difficult, and hinges partially on social norms. It is all well and good to mandate that drivers not exceed 100km/h, but having a speed limit is worthless if it is widely ignored. While my experience is anecdotal, the going rate on the 400 series highways in Ontario (the ones I’m most familiar with) is usually at least 120km/h. Whether 100km/h is besides the point if no one is actually driving at that speed.
Having just returned from a trip through Minnesota and North Dakota, the highways didn’t seem any more dangerous than Canadian highways (in fact, given their better design, they actually felt safer). This despite their speed limits of 70mph (113km/h) and 75mph (121km/h). There are currently 35 states with speed limits between 70-85mph (113-137km/h).
Determining the optimal speed limit is difficult. But it needs to be a limit that most people can actually follow. Our current set of speed limits does not conform to social norms, and, hence, results in minimal and arbitrary enforcement.
While one could argue that increasing average driving speeds might increase the severity of accidents, consider this statement from University of Toronto traffic engineer Baher Abdulhai:
“What happens now is you get most people driving between 100 and 130 and some people driving at 100, so there’s a spread in speed values, which leads to an increase in road rage, aggressive passing on the right and, really, chaos. It’s not speeding that kills, it’s speed variation.”
This leads to an interesting question: is it better to have most people driving at sub-optimally high speeds, or have a relatively even division of people driving at optimally safe speeds, and people driving at sub-optimally high speeds? I’m inclined to buy the argument that variance matters more than speed level.
Though I am not sure at the moment of the optimal speed limits or enforcement levels, there seem to be good reasons to give the idea of increasing speed limits serious consideration.
