by Jim Rose in applied welfare economics, health and safety, transport economics

I had an unnerving near miss at my local roundabout tonight with a bike as I was turning left. The bicycle appeared out of nowhere on my right in the middle of the roundabout as I glanced of the left to check again while turning so I crash stopped.

The bike had a light at the front but wasn’t visible to me until it was halfway into the roundabout when I glanced of the right again. The bike rider was going into that roundabout at a good speed against a wall of car lights behind it, so it was impossible to see it until it was close to the door of my car because of the background of car lighting after dark.

Bike riders have an overinflated self-perception of their visibility at night. Not surprisingly, more accidents happen during peak hours when drivers think motorists can see them when they cannot.

Even on an empty road, bicycles are not easy to see at night – certainly there not as perceived as quickly as cars. Bicycles are a much more dangerous transport mode than driving a car.

A recent study found the bicycle lighting is overrated as a method of making bikes more conspicuous – perceptions of visibility do not necessarily match reality:

The presence of a bicycle light, whether static or flashing, did not enhance the conspicuity of the bicyclist; this may result in bicyclists who use a bicycle light being overconfident of their own conspicuity at night.

Consider this thought experiment. Suppose bicycles have never been invented until tonight. The business case for allowing them on to the road is as follows:

Certain pedestrians should be allowed to share the road with cars as long as these pedestrians travel quickly on a metal contraption that is slower than cars, but still allows them to move relatively quickly; These fast moving pedestrians are near invisible in rear-view mirrors; These fast moving pedestrians should be allowed on the road at night when their visibility is poor against an every-varying contrast of a moving landscape; These pedestrians moving quickly at night on the road are overconfident in the extent to which drivers perceive their presence against a moving landscape; and Older drivers are 50% less likely to perceive the presence of a bike with lights and illumination at night than are younger drivers.

Would that business case pass under the precautionary principle championed by environmentalists, many of whom are bicyclists? Would that business case pass under normal cost benefit analysis? I say no. Bicycles at night must go.