Local authorities! Do you have a problem with speeding motorists?
Put up temporary traffic lights on any straight bit of main road that's longer than about 50 yards, preferably near junctions with busy A-roads or the motorway. Make sure each lane gets 4-5 uninterrupted minutes on green, that way long queues will form on the other lane and congestion will spill over into adjacent streets.

A few sets of lights in strategic places will bring down the average speed of traffic in your town to under 5 mph in daylight hours.
( The Mock TurtIe ™ --- Thinks you are a cunt, on, Sun 5 May 2013, 15:59, Reply)