This is one of my major issues on my commute, not the cars, buses or lorries, but the minority of cyclists treating a canal towpath as a racing circuit, so much so that during the summer I've taken my chances on a very busy road at rush hour rather than witness or be involved in the inevitable accident on the canal. There are constant complaints in the local paper about speeding cyclists on the canal, it's only a matter of time before they install speed restrictions. If you want to go fast use the roads.