If its just laziness, this could be enough to embarrass the authorities into improving enforcement. Of course, if it's corruption then it's unlikely that his cameras are going to last very long.

Open source number plate recognition software appears to exist. Now all you need is a couple of cameras and a server. In fact, you don't even need a real-time link to the server. You could store the photos on the camera and then process them off-line.

In the UK, reduced speed limits due to road-works on motorways are often policed using average speed cameras. These use number-plate recognition to identify cars as they pass cameras at two or more points, then calculate the average speed based on the distance between the points. The advantage of this as a home-brew solution is that you could build it with off-the-shelf equipment - no radar units needed. There's also no need to paint lines on the road or to calibrate a radar unit. It's also possibly more effective - there's no point slowing down just for the trap and then accelerating away again and it's passive, so radar detectors don't work. You'd need some license-plate recognition software, but I imagine there are free or cheap solutions available for that now. You'd need to ensure that your jurisdiction allowed you to photograph cars on a public road and store details of their number plates and you'd need to find a way to convince a court of the fidelity of the time-stamps on the photos (maybe have an OTS unprogrammable GPS unit sitting in view of the camera?).

Catching speeders imposes no new restrictions - it's just about enforcing the rules that are already in place. So presumably it requires much less effort from the politicians / authorities, which makes it a more achievable objective for this guy, who's just a private citizen.

They have to plan their journeys around accessible stations, just like in the US. Incidentally, the "Stand on the right" notices all over escalators on the underground are supposed to (and generally do) achieve exactly the the effect that you describe. Oh, and you should probably have offered to help the old ladies before you were asked ;-).

I'm a maths researcher. At my previous and current institution there's a mix of Windows, OS X and Linux. The people doing more serious coding tend to be on OS X or Linux - often both. IMANPE (In my admittedly narrow personal experience), I have never come across any research level codes that are Windows-only and I often use libraries that assume some kind of Make-style UNIX build environment.

I'm a mathematician and I resent that wildebeest

Three years is a bit late, though. I hear that a child at a year old is most delicious, nourishing and wholesome.