Speeding on residential/neighborhood streets is a common citizen complaint, but previous research on the
effects of lowering speed limits has been limited mostly to high-volume, high-speed roads. On such facilities, studies
indicated that a reduction in speed was not commonly attained by reducing the posted speed limits alone. This paper
describes residential studies in the United States in Springfield and Columbia that found speed limit reductions from 30
mph (48 km/h) to 25 mph (40 km/h) did produce statistically significant speed decreases. In addition to the speed limit
reduction, other issues investigated were the use of specialized speed limit signs containing a yellow border and an
additional safety message, pace car stickers and neighborhood educational campaigns. The engineering studies were used
by each City to guide their decisions to lower residential speed limits citywide.