RESULTS OF A TRAFFIC FLOW SURVEY AT NEW RURAL ROUNDABOUTS IN HUNGARY Comparison with Four Leg Priority Junctions

Abstract

A traffic flow survey was made at new rural roundabouts in Hungary with a video camera. The traffic volume, the critical gap and the average circulating speed on the junctions as the most important parameters of traffic flow were examined. The results include the maximum hourly traffic flow, the largest fictitious hourly traffic flow as the parameters of traffic volume and the average circulating speed of three different types of vehicle such as passenger car, light lorry and heavy truck. The fictitious hourly traffic flow was calculated with neglecting the traffic free periods in the following steps: - the number of passing through vehicles was summarides at a given geriod subtract- ing the inactive time of traffic (inactive time means: there was no vehicle on the whole junction), - a fictitious headway was determined as a quotient of the busy time and the number of passing through vehicles during this interval. -fictive hourly traffic was then calculated as a ratio of 3600 seconds and the fictitious headway. Circualting speeds of the vehicles were examined under two different conditions: - vehicles starting from standing position, - vehicles enterning the roundabout with flying start.