he also said it bollards could replace speed cameras and speed bumps... it was only later he started to talk about 20 mph so its not overly clear what he has in mind.
while 20mph mihgt not cause cars to go out of control any time a car gets caught on one ( which would be much more frequent if these are on most roads rather than on restricted bits that only buses or other limited road users can use). You've then got what could be a busy road in a busy town blocked until the car gets towed away causing major traffic problems. And you've got the risk that the bollard hits the fuel tank or fule line. Then the whole road would be closed until its cleaned up.
The clip shows the bollard rising after a preset time and catching someone. These bollards would have to be fired of in response to a moving vehicle and would be harder to predict where tehy will hit the car.
Perhaps you could have limited success with it but its never going to be deployed because it would cause chaos, fail to do the job ( motorcyclists just avoid them) and could be a legal minefield if one goes off by mistake.
Fod
