Some drivers don't think about the possibility they're not the only person in the world and others can be quite aggressive when cyclists are on the road. Some drivers go out of their way to harass cyclists.

There's a famous story of a cyclist in Canberra who got so peeved about drivers who seemed to see how little clearance they could give him while overtaking at speed (in the suburbs) that he machined a pointed extension to the axle in his offside (the right-hand side in Oz) pedal. The extension terminated in a point 9" further outboard than the normal axle on the pedal.

The first vehicle he scored (in the literal as well as the figurative sense) was a Volvo (Volvo drivers are regarded by many in Oz as the lowest form of recognisable life) which overtook him in the lane nearest the kerb on a road with four lanes in each direction. It was in broad daylight and the cyclist was wearing all the usual reflective clobber and also had a flag about 4' above his head, so the driver couldn't reaaly complain that he was hard to see.

The Volvo driver was so incensed about "malicious damage" that he took the cyclist to court. After both parties had given evidence the magistrate dismissed the Volvo driver's allegations and instructed the police to charge him with dangerous driving, on the basis that overtaking within 9" of the end of the normal pedal was far too little clearance to be be regarded as safe driving.

Score 1 for cyclists.

Cheers, Rowan