MFAFF -- thanks for the UK perspective.
Begin Rant
FWIW, I'm right there with ya. I think safe driving is good, and roadway accidents are bad. I also think that a significant portion of our traffic safety programs -- worldwide, even -- are more geared towards $$$ than safety. The reason is just like TG's point -- it's really easy, almost trivial, in fact, to pick out speeders. OTOH, it's very difficult to tell if a driver's distracted, not paying attention, has bad brakes, etc.
Here's a scenario. Assume both cases are relatively low traffic density.
1 - Ford Explorer, one corner tire has been replaced with the balloon spare. The two right rear windows are covered over with cardboard. The right side brakes failed long ago, so the driver stops the car using only the left side brakes. The exhaust gasket has also failed, so the driver can't hear anything over the engine. He's also talking (yelling) on his cell phone and eating a cheeseburger. .... He's obviously unsafe, and an accident waiting to happen, but he's legal at 60 in a 60 zone.
2 - Shortly after the Ford follows a sports car. He's wearing 11's and 9's (rear and front), with the biggest Brembos he can fit inside the rims. The suspension is precisely tuned for the weight of the car, which is insignificant -- he's got it down to 2100lbs, fully loaded. He logs more track hours in a given week than most of the rest of us will get in our lifetimes. The car obviously contains no stereo, and his cell phone is in the trunk, so there's no concern for distractions. He's wearing his harness, has slept well, has no psychological or emotional distractions, and is utterly focused on driving. But he's doing 70 in the same 60 zone.
The first driver can go from 60-0 in, say, 300ft, with his bad brakes. The second driver can stop his car in perhaps 150ft, even from 70. The first driver is unlikely to spot any hazards or potential accidents until long after it's too late. The second driver is paying attention, and is likely to anticipate and correct for other driver's mistakes. The first driver, if involved in an accident in his 7000lb behemoth, will likely demolish the average 2700lb econo-box. The second driver, if involved in an accident, could probably only kill the other driver by beating him with the remants of his car, after the accident.
But the first driver is legal, at 60 in a 60 (or by our police definition, "safe") while the second driver, at 70 in a 60, is illegal (or by our police definition, "unsafe").
End rant.
FWIW, there are some good cops. My boss is married to a Fresno-based CHP who's excellent. He's the guy who pulls over people for dangerous lane changes, for raw driving rudeness, and for watching TV while driving. Seems like there's a couple of cops who frequent this board who also "get it." It's just so much _work_ to "get it," though.
Dan