Tuesday, 9 February 2016

A modest proposal for dealing with red light runners

Drivers who run red lights is one of the banes of modern driving (and cycling, and crossing roads as a pedestrian). And periodically people vent to the media about it (like this recent opinion piece by Barney Irvine of the AA):
An epidemic - that's how Auckland AA members describe red light running in their city.
It's a road safety issue that has people scared, frustrated, and crying out for action. Every year, two-three people are killed and over 300 injured in accidents caused by red light running, imposing a social cost of close to $50 million on the country.
Irvine's proposed solution is to increase the number of red light cameras. I want to suggest an alternative proposal. But first some background.

While some drivers are careless or inattentive, I'd argue that most drivers are totally conscious of running a red light. A rational (or quasi-rational) driver weighs up the costs and benefits of running the red light, and if the benefits outweigh the costs they run the light. The benefits are the (often small) time saving from not waiting for one phase of traffic lights.

The costs? There's a probability of having an accident and the associated costs (of car repair, but also potential accident-related health costs). The probability of an accident (and facing the associated costs) increases the longer after the light has turned red, which explains why more drivers will run through a red light 0.1 seconds after it changes than 3 or 4 seconds after.

There is also the probability of being caught and fined (currently the fine is $150 for failing to stop at a traffic signal). The probability of being caught is probably fairly low (essentially a police officer would have to be at the same intersection to see you do it), so the probability-adjusted cost of fines is pretty small. Irvine's solution would increase the probability of being caught (on camera), and increase this cost.

However, there's another problem with the probability-adjusted cost of fines. The fines occur at some time in the future, and we know that people value costs (and benefits) that occur in the future much less than immediate costs and benefits. So, the cost gets discounted and compared with an immediate benefit. And for some drivers, the cost (small probability-adjusted cost of accident plus smaller probability-adjusted cost of fine) is smaller than the benefit (time savings), and they run the red light.

My modest proposal is to make the cost more immediate, and costly in time as well as monetary terms: Let's have road spikes that deploy on the white lines at traffic lights, 0.1 seconds after the light turns red. Any red light runners then face an immediate and severe cost of four new tires (blown out by the road spikes). On top of that, it pretty much ensures that there would be no drivers for whom the benefits of red light running outweigh the cost - because the time cost alone (of being forced to stop because all your tires are flat) is sure to exceed the time benefit of running a red light. And that's without considering the monetary cost.

And before you think this idea is crazy and wouldn't be implemented, consider this video of cars crashing into automatic bollards designed to reserve bus lanes for buses alone, which follows a similar principle:

Maybe forcing drivers to face a higher cost of their actions isn't so crazy?

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