Speed zoning and control

Field studies have been conducted at a limited number of Texas sites to investigate and evaluate speed zoning procedures 1) at speed zones in rapidly developing urban fringe areas, 2) at transition section speed zones on highway approaches to cities or towns, and 3) at speed zones recently lowered below the 85th percentile speed in response to local community pressure. Posting speed limits below the 85th percentile speed in rapidly developing areas had no conclusive effect on speeds or accidents. Studies at transition section speed zones showed that fewer speed limit signs could be used to adjust between rural and urban speed limits without adversely affecting traffic speeds. Studies at speed zones recently lowered after considerable community pressure showed that overall speeds were also not lowered by reduced speed limits. These results come from a limited number of studies, and should not be taken as totally conclusive. The studies do not support a departure from the 85th percentile speed criteria currently used in Texas speed zoning procedures. It is recommended, however, that the procedures emphasize that fewer speed limit signs may be used in transition sections (a).