Most people use cars or other automotive vehicles (e-bikes, e-scooter) to get faster from point A to point B. However, speed of traffic causes trouble for other groups of mobile persons. Demands on attention rise, despite the abundant use mobile phones even during driving a car. Mapping systems and services from A to B have become an almost daily exercise. Statistics on road accidents that involved inadequate speed are between 20 and 30 percent of all deadly road accidents, depending on the source of information and country (Example D). Frequently, speed is not the only cause, but other behavioral mistakes occur jointly.
Traffic signs are a basis to make drivers aware of accident prone locations. Too many of them may even lead to the opposite effect of ignoring the signs. Reducing the speed of traffic in inner cities is a steep challenge and many cities invest substantial amounts of money and effort to monitor and try to control better excessive speed. Schools, sports centres and shopping areas are all hot spots of automotive and pedrian encounters. They deserve special attention. Penalizing excessive speed is one way to nudge behavioral change. Although the statistics on the huge amounts of penalties awarded does not seem to alter the behavior of traffic participants in the short run. For some it appears to be a regular part of their budget of mobility with no consequence for behavioral changes.
For years the dangers of inadequate traffic speed in cities made young families and older persons leave more risky inner cities, but adaptations of hot spots and increased control systems seem to work in the long run. The “externality” of inadequate traffic speed is higher costs for the health system and society at large. About time to make a “behavioral turn” in traffic speed. 
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