The additional rules are normally from valid considerations, e.g.: * Whether its ok to stop temporarily depends on how busy the road is. * The parking spots a

The additional rules are normally from valid considerations, e.g.: * Whether its ok to stop temporarily depends on how busy the road is. * The parking spots are on a major road that has a lot of traffic from commuters - you need the extra lane at certain times. * The parking spots are near a school or other attraction that has predictable bursts of parking demand. You can resolve some of this by being overly restrictive about parking, but that's a suboptimal solution. If the parking spots are near businesses then I can guarantee that there will be lobby groups very unhappy with the suboptimal solution.