Some interesting stuff here, including links to more studies showing similar results in different countries.
The summary is that the reason motorists break more laws is that speeding is so common.
I don't think this is because motorists are all evil and cyclists are all saints. Probably, the reason motorists break speed limits is that it can be relatively difficult to keep cars below the speed limit. It's all too easy to absentmindedly speed up. It's also, perhaps becuase of this, widely seen as socially acceptable to break the speed limit (speaking anecdotally).
One interesting thing here, which may not surprise regular readers of Fuck Cars, is that better cycling infrastructure leads to less lawbreaking by cyclists. As is often the case, it's the design of roads and cities that changes behaviour, not abstract appeals to road users to be sensible!
@frankPodmore @gowan I guess the idea is that if you mandate helmets it will reduce bicycle use (which may be part of the reason you’ll seeess deaths). Less cyclists in an area raises the risks for those cyclists that remain. Drivers feel more comfortable with helmeted cyclists, and studies show they drive closer to those cyclists that wear helmets compared with those that don’t (see ‘risk compensation’)
I wear a helmet cycling kids to school fwiw.