Should you cut through a car park or petrol station forecourt to avoid a traffic light?

Does it annoy you when people cut a corner through a car park or petrol station? You’re not alone, but is it OK to do it?

Here are the advantages:

1. Less time idling or crawling slowly in traffic means less pollution
2. One fewer car waiting at the lights means congestion is reduced at that spot
3. The driver gets some benefit knowing that their trip is shorter
4. If a person is behind you that genuinely needs to go to the shortcut (e.g. to get fuel), they might not have to wait in traffic so long.

And the disadvantages:

1. Rushing through a shared vehicle/pedestrian zone, like a car park, increases the risks of an accident
2. Shifting the congestion from one point doesn’t necessarily mean it won’t have an effect further up the road. I.e. you just reach the next set of lights sooner and make congestion slightly worse for those who didn’t take the shortcut. It only alleviates congestion here if all waiting vehicles can get through the green light phase before it turns red
3. Additional traffic on private property causes wear and tear that the owner has to subsidise. This includes having to repaint lines and repair potholes.
4. Additional traffic through private property adds congestion for those genuinely using the area.

In terms of what to do with the extra time, if you save 30 seconds each time and you do it once a day for 5 days a week on working days, you have saved over 1.5 hours at the end of the year, not including any gains you might make by beating a traffic light phase you may have missed had you waited. 1.5 hours idling is around 2 litres of fuel, but the net saving depends on your driving style through the car park and how many changes of direction you make in the car park. If you are avoiding only one 90-degree turn at traffic lights, but you’re winding your way through four 90-degree turns and multiple potential stops in the car park, you’ll be using more fuel and wearing your tyres out more quickly taking the shortcut.

Therefore, it barely seems worth it.

There are places this happens where it’s negligible there’s any extra gain, or it actually takes longer. For example, in Greenlane, Auckland, drivers try to cut through the supermarket car park to try to shortcut the queue turning left. From observation, most times, the vehicles taking this route make no extra progress and often are still waiting to turn out of Marewa Road as you go by. In fact, Google Maps says that it could possibly be longer to take the ‘short cut’ – 2-6 minutes the regular way or 3-6 minutes through the supermarket car park.

So, the conclusion is that the disadvantages possibly outweigh the benefits and certainly create negative outcomes for those genuinely using the property.