What distance from the preceding vehicle should you maintain standing before an interection, waiting for the green signal?

You should maintain a distance that allows you to pass the vehicle in front without having to reverse, for example, in case it breaks down. A commonly accepted and safe rule is to stop at such a distance that, from the driver's seat, you can see where the tyres of the preceding vehicle touch the road. Such a buffer ensures safety and the ability to manoeuvre in an unforeseen situation.