The measure is aimed at reducing accidents in urban areas with heavy pedestrian traffic and narrow streets, marking a major shift in the country’s traffic rules as these roads account for around 70% of all ordinary roads nationwide.
[…] above [30 kph] the risk of pedestrians suffering fatal injuries in accidents is said to spike.
[…]
The aim of the speed limit change “is to prevent accidents by stopping dangerous driving, such as failing to slow down even on busy streets”
broader city design too, you shouldn’t really have to spend much time on residential streets. It should be like a circulatory system, most of the traffic is on a small number of high-speed high-capacity through-roads and then it quickly splits apart into a bunch of smaller local streets.