My journey to work takes me through one of the most speed camera intensive routes that I know - A12 - Blackwall Tunnel - A2. There must be 10 cameras over a distance of roughly 20 miles. Having regularly observed the behaviour I would like to make a few points:
I know where the cameras are so I ensure that if I have to slow down, it is gradual and normally using the gears on the inside lane so that people can overtake if they want to. Others are not so considerate; heavy sudden breaking, 'undertaking', swerves into other lanes etc. are all dangerous and cause an additional hazard that would not be there if the cameras were absent.
Just checking the speed does not check how people are driving. Every day I see exceptionally stupid driving, frankly, some of it from me when frustration overcomes my desire to be safe. Due to the total absence of police (I can’t remember the last time I saw a patrol car, marked or otherwise), this is doomed to continue.
Conclusion: A road that was previously free flowing has been made dangerous and 'lumpy' by the addition of an excessive number of cameras. Dangerous driving is totally ignored but I bet that the revenue is fantastic (I see several flashes a day on my short journey). Where will the revenue go? More cameras I suspect.
P.S. If anybody has accident stats for this road (before and after the cameras) I would be very interested to hear them.