Control and traffic signal warrant assessment of intersection sites

Abstract

Frequent evaluations are required to upgrade mobility and safety at intersections. This thus paper proposes a typical scenario to identify suitable controls for installing appropriate traffic signals.Five individual intersections were studied within the Babylon province, of Iraq, and graphical methods were used to identify suitable controls. Three graphs were adopted based on recommendations from the Institute of Highway Transportation (IHT), Department of Transportation (DoT) and the Iraqi Highway Design Manual (SORB). In addition, warrants for traffic signal installation according to the Manual Uniform Traffic Control Devices (MUTCD) regulations were checked with HCS 2010 software.According to IHT recommendations, three of the five intersections should be of a priority type and the others should take on a grade separation and a roundabout or a similar signal type. According to DoT, three of five intersections should be roundabouts and the rest Ghost Islands. The SORB recommends that all intersections should be controlled or altered to interchanges. Optimisation of suitable controls for each site should thus take all three methods into account in view of restrictions on area and budget. According to MUTCD, all of the intersections justify the installation of traffic signals, though further evaluation complementary to the proposed scenario would be useful.