Except if it is let out time at school...
I have been blocked (on more than 1 occasion) by parents that just stopped because their little one was waiting by the kerb. Air horns and siren did little to convince them to move.
Mind you, I think the visit from the local Sargent with a fine in his hand for them has made them think twice about doing it again.
And if we had a job on a Saturday morning, we took the long way round, cause it was quicker than trying to get up the main street. Sea Changers just didn't get it, and caused us more problems than the delay was worth.
The exception to this, are the real country towns. The locals know what a siren means, and you can run the entire main street without being hindered.

