What The...?

How often does this happen to you? You're behind a vehicle on the highway and they're going 10 under the speed limit You're waiting to pass but there's no breaks, then you come to a passing lane and the opportunity to get by without concerns for oncoming traffic. But, just as you begin to ready yourself to cruise by the slower vehicle begins to speed up and is now going 10 over the speed limit and preventing you from passing. Not only that but once they get back to single lane they slow down again and resume the slower pace! Like...what the...!!

It happens to me about twice a trip when I head up to our camp along Hwy 22 North, where there are long stretches of road with no passing and just a few passing lanes built on some of the hills along the route. I used to think this sort of behaviour by other drivers was induced by some sort of malice on the part of the other driver, a sort of "I don't want you to pass me" attitude or something. However, after sharing stories with someone else who had a similar experience, I was prompted to look into it a bit further and do research which produced some very interesting results.

First of all, it is a very, very common issue, and not just in this country. A worldwide phenomena and the cause of much chagrin for all drivers. And, since it is such a common issue perhaps that is what prompted research into the cause, with several studies being performed in Europe.

Basically, the study found that drivers perceive that the road is safer when it is wider, plus generally, passing lanes are newer, less travelled upon and thereby smoother and quieter, also adding to the idea that there is less danger. One study in Europe found that by increasing the width of a road from 6 m to 8 m, the speed of traffic increased from 80 kmph to between 90 kmph and 100 kmph.
Not that this concept is something new either, and many a road designer and engineer use what is called the 'gateway treatment' to slow traffic down as it enters urban areas and the suburbs. Sometimes narrowing a roadway with 'traffic bulbs', or signage and line painting, can encourage drivers to reduce speed as they get squeezed into the smaller lanes.

Consider some of the physical factors that influence this. One is risk homeostasis, as explained in a hypothesis posited by Gerald J.S. White, professor of psychology at Queen;s University in Kingston Ontario. It deals with the notion that every person has an acceptable amount of risk that they are find tolerable. The environmental factors that create the perception that there is less danger, i.e wider, quieter and smoother roads, raises that risk level and results in a willingness to drive faster. Consider the similar effect when elderly people drive and tend to be a lot slower. The average person loses about 3% of their peripheral vision with each decade they live and that loss of field of vision gives the perception of more danger, resulting in lower risk tolerance and the slower driving speeds
The reality is that passing lanes are built with the perfect formula for deterring passing by giving all the stimulus that encourages the slower vehicle to speed up, thereby preventing the vehicle following from getting past. To paraphrase Hanlon's Law into a kinder, more gentle version "Never attribute to malice that which can be adequately explained by human frailty"