MULTIVARIATE COMPARATIVE ANALYSIS FOR SELECTION OF INTERSECTION CONTROL (CASE STUDY FOR SELECTED UNCONTROLLED INTERSECTIONS IN HAWASSA CITY

Abstract

Uncontrolled intersections that are found on major road carrying a higher traffic volume generally have traffic safety and operational problems. This is due to the crossing and turning movements at this intersection cannot be satisfactorily managed with existing uncontrolled intersection. At major arterial road intersection with medium and high volume roads where grade separation can‟t be justified traffic would generally be controlled by either signal or roundabouts. The main objective of this thesis is to assess and find out optimum intersection control mechanism from roundabout or signalized intersection for existing uncontrolled intersection of shell and Addisu Menhariya in Hawassa city. These intersections are selected because both are found on major road carrying high traffic volumes (AADT) that justify the introduction of roundabout or signalized intersection based on ERA intersection selection criteria. The methodology that is used for selection is multivariate comparative analysis that uses cost, operational performance and safety performance as evaluation criteria. The traffic, geometric, cost, signal and crash data‟s are collected to make Comparison. Operational performance analyses are made using HCM 2010 methodologies incorporated in SIDRA Intersection software 5.1.The safety performances are measured using mean crash rates and causalities for similar intersection types for years from 2014 to 2018 G.C for millions of entering vehicles to intersections. The costs that are used for comparison are estimated initial costs for alternatives based on current market prices of the city and operational costs that are found using SIDRA Intersection software 5.1.The result show that proposed roundabout and signal intersections will serve LOS C and LOC F with existing traffic condition in both intersections respectively. The summary data indicates that the casualty crash exposure rate at roundabouts in Hawassa city is approximately 19% less than the casualty crash exposure rate of signalized intersections, when averaged across all crash types. The fuel costs and operational cost for roundabout intersection are also lesser than alternative signalized intersection. But the initial cost for roundabout is higher than proposed signalized intersection. Roundabout options are finally recommended for existing uncontrolled intersections of shell and Addisu Menhariya in Hawassa city