Bike collision on canal path

There's no reason to go fast along there, it's narrow and crowded, tow paths are for pootles, not fast commutes.

On the segments of the canals in london, this is true, its very very busy, narrow and the people that do use it are generally oblivious to everything else.

In other parts of the country, they do make for brilliant, quick, traffic (vehicle & ped) free routes to work :p And the odd people you do come upon are generally friendly as hell or at least acknowledge your presence etc etc.
The only real hazards are of the steaming pile variety.