There are numerous references to increased congestion as a result of the reduced speed limits in built-up areas, but the UK has a fairly strong "You should always be 2 seconds behind the car in front" element to driving rules, and naively if there's two seconds between every car then the number of cars passing a particular point in a given amount of time is going to be the same regardless of how fast they're travelling, so is there a real model where a lower speed limit reduces throughput in a meaningful way without violating this constraint?
