In the UK, people against 20mph limits often oppose them while claiming that they're never able to get above that speed anyway. Why are they opposing it then? The answer is simple - it's not true and on many streets you're able to drive at 30 or over (if you disregard other people's safety). I would sincerely doubt this was any less the case in the US where traffic lanes even on 'tight' streets seem to be stupidly wide. Many drivers also seem perfectly happy to break the speed limit in their desperate rush to get the back of a queue or to a red traffic light.
It's all very well having cars going at 40mph past you on a bike until the driver of one of them gets distracted or makes a simple mistake and hits you. Then you'll wish they were doing 20!
