The stats shown earlier in this thread by miketually were from 2004!?
The statistics don't take into consideration the density of population, number of vehicles, accidents per capita, or tell you at what speed the vehicles that did the killing were travelling at. Neither do they show which type of streets the accidents happened on, or whether the pedestrian was behaving recklessly. So the stats are a bit useless.
I think narrow residential streets, streets with high numbers of pedestrians, or any streets with parked cars should have a default 20mph limit, but on condition that all forms of traffic calming in these places are removed.
Urban freeways and main routes should have limits set according to risk to pedestrians and other road users. If main arterial roads were restricted to 20 mph, people would just ignore the limits.
These days, the sheer amount of traffic lights, traffic calming and other things that impede a driver's progress is cumulatively enough wind them up over the course of their journey. I find people are more inclinded to jump red lights, not give way, accelerate towards people crossing roads etc. I believe this behaviour is due to sheer frustration with the "safer" road schemes created by the numpties in council highways departments. These people overzealously interfere with our roads in the interests of "road safety", citing how their intervention saves lives! I reckon that most schemes are implemented because of a few complaining residents, not because of actual accidents.
I could quote several alterations near me that have been created lately, which are just dangerous and have caused delays and frayed tempers. There was no issue before the council came along and wasted our ever scarce public money!
One type of traffic calming is particularly dangerous in my opinion. Namely where tables are installed on road where pedestrian trafic islands have always existed, but where there is no pedestiran crossing. This feature clouds who's right of way it is, giving pedestrians the feeling they are using a proper pedestrian crossing when they aren't. There was a fatality on one near me last year. Both driver and pedestrian were in their 70's and the driver thought he had right of way. Clearly, the deceased pedestrian did too. Tragic!