So you're saying that everyone without stop/start sitting at the lights with their engine still running is breaking the law?What a load of rubbish. 100% if you're stationery you should put it in neutral, handbrake on, let Stop/Start do it's thing.
It's specifically against the law technically, Rule 124, "you MUST not leave a vehicle engine running unnecessarily while the vehicle is stationary on a public road"
I don't think that's what that rule means...