> Get the average speed, add 5, and post the sign. A common method for setting speed limits in the past was the 85th percentile speed. I agree that changes to

> Get the average speed, add 5, and post the sign. A common method for setting speed limits in the past was the 85th percentile speed. I agree that changes to road design are a good idea when a significant number of people drive too fast, with "too fast" being determined by risk factors that are not necessarily obvious to drivers. Adding curb extensions, chicanes, or narrowing lanes by painting new lines are some inexpensive options for encouraging slower driving. I'm against nannies built into cars or heavy punitive enforcement.