Walmsleys wrote:

Driving trainers always advise being in neutral when you're at lights, etc in case someone rear ends you, your foot slips off the brake and the car drives into the car in front!

I have been on several driving courses over the years - all job related and insurance reducing

I don't completely agree with the "always" as I have been taught to control the vehicle behind me and bring it to a stop before I do. Stopping so that I can see the tyres of the vehicle in front contacting the road - thus giving a safe stopping distance and ability to maneuver around the car in front should it fail to move off or . . . .
If you slow down and stop but there are no cars behind you, then good observation will ensure you are aware of an approaching car from behind. Should it look like it is going to crash into you, being in gear and stopping as above will allow you to potentially have time to move out of its path.

I have seen a Police motorcyclist avoid certain death when a transit van drove straight into an articulated lorry that had already stopped. He was behind the lorry, saw the van skidding towards him and changed lanes pdq.