Traffic Speed Report No. 119

Progress Report No. 119 is the report of the June-September 1985 study of free flow automobile and truck speeds on tangent, level and dry sections of rural interstate, urban interstate, 4-lane and 2-lane highways in Indiana. The results of this report show that all types of vehicles, on all types of Indiana highways, had an average free flow speed of 57.2 mph in 1985. This indicates a reduction of 0.5 mph from 1984. If the two urban interstates are excluded, the average speed becomes 56.9 mph in 1985. This indicates a reduction of 0.7 mph from 1984. This report includes a chart that graphically summarizes the results of summer free flow speed monitoring since 1975.