If I report intentional dangerous driving to police, will it have any effect? Today I was riding ~3 feet out from parked cars (dooring is the most common way to get killed) and this pickup truck comes up behind me and just lays on its horn for an entire block. The driver was also revving his engine and coming within a foot or two of my back wheel.

The driver intentionally cut me off forcing me to swerve to avoid the back of their truck. As he passed me the passenger rolled down his window and informed me (using very crude language) that I should get off the road.

I have had three or four incidents like this in the last year and I am getting increasingly infuriated by them.  They have all been on residential streets that drivers are using to avoid the city's arteries.  I do my best to be courteous and don't accept this behaviour.

I think that I need to do something so that I don't end up throwing my bike through someone's windshield doing something inappropriate.

I have been considering getting a camera on my bike but wonder if this would be useful.

Question:  Has anyone ever contacted their local police regarding aggressive drivers?  Were the police helpful?  Would video evidence be useful?  (I suspect that a camera would help to remember an aggressive driver's information even if video evidence was not required by the police).

Question: In the case of an accident would video evidence be useful to press criminal charges against a driver?  If I am injured would video evidence be useful if I wanted to seek damages in civil court?

I live in Ontario, Canada.

Related: "Is complaining to companies about bad driving like howling at the moon?"
I'm convinced that the prevalence of cameras is changing the attitude of certain drivers. 

For the last year or so, I've ridden with a helmet cam. I'm now on my second camera and I'm toying with mounting my old camera (lower definition, poorer lens) on the seat post to face to the rear. 

It wasn't for this kind of situation, but it would certainly be useful as evidence. If you search YouTube there are many, many examples of similar behaviour. If the police can't or won't help, just publish the footage on the web - the driver will almost certainly never see it, but you never know. 

I've had several situations where a rant from an angry driver has suddenly become an embarrassed silence when I've pointed out that they're being recorded and I'd be quite happy to post the results to YouTube, the police, their employers (this does work well if it's a work van or similar) ... 

There have been several cases here in the UK where dangerous and aggressive driving has been prosecuted successfully solely on the basis of the cyclist's camera evidence. 

On the civil side, I know personally of one accident victim who was knocked off his bike and whose claim was enormously aided by the footage from a cyclist behind them who had been wearing a camera. Anecdotal, I know, but he is certain that the claim was processed more smoothly because of the video recording.

If this seems like a good idea, the answers to what-is-a-good-camera-arrangement-for-city-riding or recommendations-for-inconspicuous-helmet-mounted-video-camera might be useful in finding an appropriate camera solution.

In the first case, though, I would definitely contact your local law enforcement agency. You never know, maybe this miscreant has done it before. If a handful of independent people all report them, there's an increasing chance of something being done. And you're raising awareness in the police that there are people willing to stand up and complain. 

It might also be worth talking to your local councilor - ask about what they might consider doing to make life safer for their electorate ...