Back to the old commute today? I’m not trapped in traffic at the moment, but remember the questions I always had in traffic jams: Why are we slowing down? Where is the accident? And who the hell started this?

According to recent research, light breaking allows cars behind you to prepare for any slowing down or traffic hazards, but heavy breaking disrupts traffic for miles. Of course, if you need to break, you should break. Here’s a summary of a mathematical traffic model:

Drivers and policy-makers have not previously known why jams like this occur, though many have put it down to the sheer volume of traffic. While this clearly plays a part in this new theory, the main issue is around the smoothness of traffic flow. According to the model, heavy traffic will not automatically lead to congestion but can be smooth-flowing. This model takes into account the time-delay in drivers’ reactions, which lead to drivers braking more heavily than would have been necessary had they identified and reacted to a problem ahead a second earlier.

So pay attention out there and I will too. We’re all responsible for traffic.