My company sent me on an Institute of Advanced Motorists course many years ago but I doubt the advice has changed 
We were told that when you were approaching a traffic light that was green, you should be making a conscious and continuous assessment of which you should do if it changed to Amber: up to a certain point, that would that you have time to stop safely and smoothly; after a certain point it would be to accelerate through the junction. Part of that decision making process includes being aware of the cars behind you and how close they are.
And yes, we were told "accelerate". By that the instructor didn't mean "boy racer" acceleration, he meant a gentle increase to get through the junction more quickly, as it is a "danger zone" so you should minimise the time that you are in it.
In the same way, you accelerate to overtake - to minimise the time that you are in the danger zone.
The key thing I learnt from that course (which was a conurbation of class/theory learning and practical sessions out on open roads: 3 of us in the car with the instructor, taking it in turns to drive so also getting the chance to observe his comments about each other's driving) was to drive mindfully - to make conscious decisions rather than to drive on auto-pilot. And to accelerate from a particular point through corners as the car is more stable if you do that (but you need to be going at the right speed before the corner to do that)