Factors Contributing to Traffic Flow Congestion in Heterogenous Traffic Conditions

Abstract

Most of the urban roadways do experience traffic flow congestion at various road sections called critical traffic points, which is partly contributed by the presence of various factors on the roadways. A number of studies have used travel time indices to determine congested links of the road networks. However, the travel time-delay based indices have found less application in the identification and quantification of congestion levels in the road networks. As a result, a limited number of studies have examined the factors contributing to the propagation of congestions at various road sections using the travel time-delay indices. This paper aims to identify factors contributing to propagation of traffic congestions at frequently congested traffic critical points and to estimate their influence on the entire road network using travel time-delay data. Travel time-delay data were collected by using test moving cars. The results indicate that low travel-delay transition index below 0.70 signify the jam and crowded traffic flow condition, while higher values greater than 0.70 indicate free flow phenomena. On the other hand, high congestion index values indicate jam and crowded flow conditions whereas the low values below 0.5 signify free flow conditions. Further, the results showed that low transition index and high congestion index values were associated with roadway design factors such as T-joints, cross joints, bus stops, humps and traffic lights, which are considered to be static bottlenecks which impedes the vehicle flow.

Spatio-Temporal Analysis of Traffic Flow on Sargodha-Jhang Road (Punjab) Pakistan

“…The highways have crossed the desired limit of traffic during the peak hours due to mushroom growth in vehicular population while no sufficient counter measures are been made in terms of road infrastructure up-gradation to an acceptable level and converting the road user from own cars to public transport system by providing a quality transport system (Naeem et al, 2018). That is why, many roads across the rural-urban connection faced congestion at certain road points called critical traffic points especially in peak hours (Chauhan et al, 2017;Mahona et al, 2019). The main objective of this research was to explore the various factors and attributes related to road network configuration contributing to an irregular traffic flow and congestion at second class inter-district national highway section Sargodha-Jhang road, Punjab, Pakistan.…”

Effects of static bottlenecks on traffic flow in urban road network

“…Macroscopic traffic flow variations are in general repeated every day still they vary in the time-of-day. Further, traffic flow may start in a very low level in the early morning and gradually increase up to the peak during morning peak hours, which is always occur from 5:30 am to 10:00 am, and evening peak from 16:00 pm to 21:00 pm (Hou et al, 2008;Mahona et al, 2019). Generally speaking, the occurrence of traffic congestion in urban road network in the macroscopic fashion shows inherent repeatability every day at different time slot.…”