Bad Car Driver No.1. Whaplode.

Last Saturday driving through Whaplode on the limit at 40mph when the leading car in my line of traffic sees a speed camera and brakes hard down to 30, obviously not aware of the speed limit he should keep to. The cars following him braked even harder swerving left to the pavement and right toward the opposite lane of traffic. Not sure who is in the wrong here, a)the bloke driving the car in front for not being aware of the speed limit and panicking because he saw a speed camera, b) the traffic following him who were obviously too close (except me, of course) or the Police/Government for placing speed cameras on straight, open roads. Perhaps they all are. Doesn't it make you angry?