Re-designing a Pre-timed signalised junction at Nakulabye for improved traffic flow.

Abstract

In the past few decades, auto travel demand in the United States and developing countries like Uganda have significantly increased, but the roadway capacity unfortunately has not expanded as quickly, which has led to severe levels of highway traffic congestion in many areas. In theory, the problem of congestion addressed through demand management and roadway expansion. However, system expansion in urban areas are difficult due to the extremely high cost of land, therefore, maximizing the existing capacity therefore often was considered the most realistic option. In urban areas, most of the traffic congestion and delays typically occur at signalized intersections. This thesis aimed at proving the hypothesis that it was possible to increase capacity by establishing traffic signal timing plans that were more effective than existing plans. A new methodology was introduced as split phasing optimization as a part of intersection signal-timing design to achieve maximized reduction in overall traffic congestion, travel times and delays generally at Nakulabye signalized junction and all the road connecting network. The measurement of effectiveness in this new method was reduction in the average congestion and long queue at each leg per signal cycle. To achieve the main objective of the study, manual traffic counts surveys were carried out on each of the respective approach for 8 hours per day, with the aim of obtaining the prevailing Average Daily Traffic (ADT) classified into the vehicle categories. Detailed topographical and traffic volume count surveys were conducted in the peak hours in order to identify the issues in the traffic flow. Based on the field survey data analysis improvement measures have been recommended which makes the traffic flow smoother at this junction.