Characterization Of Major Intersections in Akure, Nigeria

Abstract

Three Tee intersection (RN1, RN2, RN₃), and two Cross intersections (RN₄, RN₅) critical to traffic flow in the study area were selected. Data on geometric features were collected using odometer; while data on critical gap and follow up time were collected with video camera placed at an elevated vantage point from the selected intersections. Average carriageway width of 7.20 m, 7.0 m, and 7.15 m were obtained for RN₁, RN₃, and RN₅ respectively which is less than 7.30 m, specified by the Nigerian Highway Capacity Manual 1976; which reduces the Level of Service (LOS). The operating LOS for the Tee and Cross intersections, were “LOS E” and “LOS F” respectively indicating that travel speeds were substantially restricted and roadway operations were with extreme delays when compared with the standard in Highway Capacity Manual 2000 (HCM 2000). The analysis of the critical gap using logit and Raff methods yielded average values of 7.46 sec, 8.02 sec, and 8.07 sec respectively for RN2, RN3 and RN4 which are higher than the recommended value for left turning in the HCM 2000; indicating that the subject vehicle drivers were conservatives and appeared to choose a gap that were sufficiently long to avoid a collision or major conflict. However, the values of 6.33 sec and 6. 87 sec were obtained for RN1 and RN5 respectively signifying that the drivers were aggressive at the intersections. Intelligent transport systems is recommended for traffic management in the study area