Abstract
This report is another in the continuing study of speeds of vehicles on Indiana highways. Observations of spot speeds were taken on interstate, four-lane and two-lane highways throughout the state during the April-June 1977 quarter. Analysis of the speeds showed the overall average speed for all vehicles was 58.1 mph. The overall average speed for passenger cars and all trucks was 58.1 mph and 58.0 mph respectively. These overall average speeds were similar for passenger cars and 2.0 mph faster for trucks to the speeds found in the January-March 1977 study (Speed Report No. 100). For the first time the average speed of heavy trucks (58.6) was found to exceed the average speed of passenger cars (58.1).