Vol.:(0123456789) 1 3 Arabian Journal for Science and Engineering https://doi.org/10.1007/s13369-019-04309-4 RESEARCH ARTICLE - CIVIL ENGINEERING Developing Capacity Reduction Factors for Curbside Bus Stops Under Heterogeneous Trafc Conditions Manish Patkar 1  · Ashish Dhamaniya 1 Received: 12 February 2019 / Accepted: 23 December 2019 © King Fahd University of Petroleum & Minerals 2020 Abstract Trafc characteristics of a roadway are signifcantly infuenced by bus stops, and it becomes more chaotic when a separate bus bay is not provided and the bus has to be stopped in the curb lane. The present study analyzes the efect of such bus stops on the midblock capacity of urban arterials under heterogeneous trafc conditions. Field data have been collected at six sections of six-lane divided urban arterial roads; out of that, three sections have not marked with bus stop and referred to as base sections, whereas the other three have designated bus stops and denoted as friction sections. A set of simultane- ous equations are established using speed and fow data to estimate the midblock capacity of urban roads and found to be 6000 PCU/h for one direction of fow. Further, a set of simultaneous equations are developed between the speed of a vehicle type and the densities of all categories of vehicles with densities of stopped buses in their individual terms. These equations are solved for any number of stopping buses at a fxed proportion of vehicles in the trafc stream for diferent trafc volume levels and thus get the capacity curves. It has been found that the capacity of urban arterials is reduced by 6.6–28.3% when the frequency of stopping buses is as low as 20 bus/h to as high as 120 bus/h, respectively. The study outcomes are useful for designing bus stops and at the same time estimating the capacity of such sections in order to reduce the congestion on the urban roadway network. Keywords Bus stop · Adjustment factor · Side friction · Base capacity · Urban arterial 1 Introduction Roadway capacity among the domain of transportation can be defned as the maximum hourly volume (vehicles per hour) at which vehicles can be expected to traverse a point or uniform section of a roadway during a specifc period under the existing roadway, trafc and control conditions [1]. Ideally, the urban road capacity is afected by several factors like conditions of the roadway, trafc, control and climatic variations, etc. Besides these factors, the capacity of the urban road is also a function of the side friction factors. A large number of activities that take place on the roadsides and intruding in the trafc fow, adversely afecting the traf- fc stream, are collectively mapped as side frictions. They include but are not limited to stopping buses at carriageway, pedestrians, non-motorized vehicles and irregular parking and stopping of the vehicles. The bus transport system is considered as an essential component for the efective growth of any developing coun- try. It is being regarded as a reliable mode of mass transport other than light rail transit (LRT) and mass rapid transit (MRT) systems. Generally, in India, most of the cities are having bus transport as the primary mode of public trans- port. For boarding and alighting of passengers, most of the bus stops are curbside bus stops. Under moderate-to-high trafc conditions, stopped buses create a signifcant reduc- tion in the speed of trafc stream and capacity of the road. This reduction in speed and capacity depends on the fre- quency of stopping buses. Figure 1 shows the trafc sce- narios on the urban road with and without a bus stop. The present study aims to determine the relationship between frequency of stopped buses and capacity reduction of the roadway. The study gives the quantitative measure of the impact of roadside bus stops on the capacity of the road. * Ashish Dhamaniya adhamaniya@gmail.com; adhamaniya@ced.svnit.ac.in Manish Patkar manish.patkar@gmail.com; ds14ce013@ced.svnit.ac.in 1 Department of Civil Engineering, Sardar Vallabhbhai National Institute of Technology Surat, Surat 395007, India