Development of ‘speed ratio’ based level of service criteria on undivided urban streets in mixed traffic context

Abstract

Developing countries are facing challenges in sustaining urban traffic congestion due to rapid urbanization. To manage urban traffic, a traffic engineer first needs to assess the current operational condition on urban roads. Level of service (LOS) is used to define the operational traffic condition within a traffic stream in terms of service quality that a facility is providing to its user. This paper proposes a novel approach to estimate ‘speed ratio’ by considering individual free-flow speed (FFS) of different vehicle categories. This study also provides a comparison between FFS estimated using the methods given in Highway Capacity Manual 2010 and Indian-Highway Capacity Manual 2018. LOS criteria were developed using five clustering technique: K-means, K-medoids, Clustering Large Applications, Fuzzy-C Means, and Hierarchical Agglomerative Clustering. Both internal and external cluster validation indices were used to find the optimal number of clusters and suitable clustering algorithms.