The significance of signal timing that treats bicyclists and pedestrians as second class road users

from A view from the cycle path - David Hembrow

Delays at traffic light controlled crossings


Cyclists and pedestrians elsewhere often feel that their time is wasted by pedestrian and cycle crossings which are timed in such a way that they prioritize "keeping traffic moving" over people who want to cross roads. This often causes people to cross against a red light, especially if they are in a hurry.

Here in the Netherlands, timings are quite different. This video shows two crossings which are on the route to school for my youngest daughter. She never has to wait too long for a green light, so I am happy that she is never tempted to cross while the cars are still moving.

Some years ago, I did some calculations based on a pedestrian crossing which we used together on the route which we walked to school in Cambridge. Crossings in the UK almost always work as described below. Even though the highway engineers can claim that the cycle time is the same for motorists and pedestrians, the average delay for motorists works out as far shorter than that for pedestrians:

Assuming that the junction splits time 50:50 for the two different directions, and that there is a 1 minute cycle time, a motorist can expect to be delayed a maximum of 30 seconds. Half of drivers are not delayed at all as the light is already green, and the other half are delayed by an average of 15 seconds, making an overall average delay of just 7.5 seconds for a driver.

On the other hand, a pedestrian only gets to cross if they walk right up to the crossing and push the button. Typically, the green phase for a pedestrian will last as little as 3 or 4 seconds, fitted into the 1 minute cycle. What's more, there is an initial use delay on the button intended to make pedestrians bunch up. The intention of this is to make best use of the this short time and "keep traffic flowing" on the road in the meantime.

So, you push the button. Wait, say, 10 seconds, then have an average delay of (60-4)/2 = 28s. As a result, the average delay for a pedestrian is 38s. That's 8s longer than the maximum for a driver or 5x as long as the average for a driver even though they are subject to the same cycle time.


Now I know that some people will say "it's just a few seconds", but let me explain further. At one time I would walk my children to primary school, then return, walk again to collect them, and return again, using this crossing four times a day. That means that on average the pointless extra delay would consume one and a half minutes day - about as long as it would have taken to make one of the whole journeys by car. I literally worked the numbers out while waiting for a green light to show.
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http://hembrow.blogspot.com/2011/04/delays-at-traffic-light-controlled.html

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