The Views of People About the Effectiveness of Flyover System in Dhaka City

International Conference on Recent Innovation in Civil Engineering for Sustainable Development(IICSD-2015)

Department of Civil Engineering

DUET - Gazipur, Bangladesh

A Study on the Congestion Level and Delay of Mirpur Arterial using ArcGIS

T. Ahamed1, Prof. Md. M. Rahman2

Abstract

At present, traffic congestion problems in major corridors of Dhaka city are getting worse day by day. The objective of this study is to represent the severity of traffic congestion on a major arterial (Mirpur Road) of Dhaka city (Bangladesh) using ArcGIS. The congestion level of Mirpur arterial was evaluated in terms of travel rate. The study compared vehicle speed, delay, and travel time, in a free-flow condition and actual condition found on the roadway and congestion level were plotted using ArcGIS. For delay measurement, twelve intersections were surveyed. Traffic volume data, speed data, cycle time, effective green time etc. were collected. Delay was calculated using Webster’s delay model. From the calculation it is evident that majority of the segments on Mirpur arterial have a congestion level between High to Very High. Due to signalized movement of huge amount of vehicles, delay per vehicle is piling up. Grade separation would be potential solution for severe congested sections. A relationship among congestion level, upstream delay and downstream delay of different roadway segments was established. Utilizing known upstream delay and downstream delay of a particular roadway segment, we can predict the congestion level without travelling and collecting travel time of that segment.

Keywords: ArcGIS, congestion level, travel rate, Webster’s delay model.

1. Introduction

1. Background

Traffic congestion is now becoming a frequent phenomenon in Dhaka city. The increase in population over the years and high rural to urban migration has led to a situation where transport services are no longer able to respond efficiently. The two arterials in Metropolitan Dhaka that are providing with mobility and access are Mirpur Road and Kazi Nazrul Islam Avenue. They are experiencing congestion and thus fail to provide their primary function of giving mobility to through traffic, like other streets in Dhaka City. Therefore, there is a need to undertake a study that will assess congestion level and delay based on some established measure of effectiveness.

1. Purpose and scope of the study

The main purpose of this study was to evaluate congestion levels on Mirpur Arterial. Congestion levels were evaluated in terms of travel rate. Moreover, the following traffic parameters of free-flow condition and actual condition were compared.

• Comparison of Free Flow Speed and Actual Speed
• Comparison of Free Flow Time and Actual Delay
• Comparison of Travel Rate and Delay Rate

^[1]

• Comparison of Relative Delay Rate and Delay Ratio
• Comparison of Travel Rate and Actual Speed

In this study, uniform delay was evaluated by Webster’s delay model in different intersections.

Then, A relationship of congestion level, upstream delay and downstream delay of different roadway segments was established so that utilizing known upstream delay and downstream delay of a particular roadway segment, we can predict the congestion level without travelling and collecting travel time of that roadway segment.

1. Data Collection Methodology

This section is concerned with the study roadway sections, surveyed intersections and the overall design of data collection scheme that was followed in this research work.

The study for congestion levels was carried out on Mirpur Arterial in Metropolitan Dhaka. It was conducted in both direction from New Market to Gabtoli. To get better results, this study road was subdivided into twelve road segments. For delay calculation twelve intersections were surveyed for vehicle volume count, geometric data, signal phasing etc.

[pic 1]

Fig. 1. Study area (Mirpur Arterial with study segments and intersections)

A public bus was used as a probe vehicle to conduct this research. The bus travelled from one section to another section and travel time was recorded using stopwatch. Vehicle volume count, signal cycle time, green time were taken manually. Geometric data was taken from Google Map.

1. Congestion Level and Delay on Mirpur Arterial

1. Congestion level quantification

Suggested congestion standards for class I arterials for tolerable congestion levels were established in accordance with National Cooperative Highway Research Program (NCHRP).

Table-1. Congestion Standards for Congestion Levels for Class- I Arterial

For evaluating travel rate as a measure of congestion level following formula was applied,

Travel Rate (min/mile) = (Actual Travel Time / Segment Length) * 26.83 ………..… (1)

For simplicity, name of the intersections were abbreviated as follows: New Market→ NWM, Science Lab→ SCL, Beximco Pharmaceuticals→ BEX, Pantha Path→ PAN, Dhanmondi #27→ DH#27, Manik Mia Avenue→ MMA, Asad Avenue→ AAv, Lake road→ LRd, Shishu Mela→ SM, Shaymoli→ SHM, Dar-Us-Salam→ DUS, Mazar road→ MZR, Gabtoli→GAB.

Table-2. Congestion Level for Mirpur Arterial (Overall-Both Direction)