How can you skid / How to do skids / skidding

Epic skid stop fail on my way to work this morning.
I'm bombing down Parkway towards Camden Town tube station when the lights at the Arlington Rd intersection **suddenly **turn amber. No problem, I think, it's an opportunity to execute a stylish skid stop.

What do you mean? That they didn't fade to amber like normal? You're going fast downhill on a busy road which is dangerous at the best of times, with no front brake and the lights changing take you by surprise. It's not your chain line that needs working on.