&gt; <i>There are plenty of documented cases of deliberate meddling with safety features to increase revenue. Look at red-light cameras, for example, where local governments have been known to change the light timing in unsafe ways in order to manufacture ticketable violations.</i><p>Didn&#x27;t know that, thanks. If you have any links to some well-documented cases of meddling with safety features like that, I&#x27;d be glad to read.<p>&gt; <i>the safest thing is to keep to the average speed of surrounding traffic.</i><p>Safest for drivers, not for pedestrians; but assuming pedestrian-free area, then ok, that is of course true for the reasons you describe (basically introducing any unexpected element on the road is making the situation less safe). But since many (AFAIR most) traffic-related injuries and deaths are caused by speeding, how do you propose we force drivers to slow down? Personally I&#x27;m in favour of ALPRs and distance-based speed checks (i.e. distance traveled &#x2F; travel time &gt; limit == you get ticketed).<p>That is, if it matters now. Self-driving cars are hopefully around the corner, and they should be able to solve this problem once and for all.