CAPACITY ANALYSIS OF HYBRID BRTS FACILITY

Abstract

Bus Rapid Transit Facility (BRTS) is a high-capacity articulated bus service with buses operating in lanes reserved for their exclusive use. It is an innovative form of transit facility, especially for developing countries like India. BRT facility is in growing stage in many countries including India. so there are places where BRT buses also have to operate in mixed traffic environment apart from other traffic environments. For example, in Ahmedabad BRT network is still expanding, so there are areas where BRT buses are operating on roads with other vehicular traffic. Therefore capacity estimation for BRT facility is an important attribute to evaluate the performance of BRT facility.The main objective of this study is to estimate capacity of Hybrid Bus Rapid Transit Facility. By the term hybrid BRT Facility in context to this study, hybrid facility indicates that a facility in which buses have to operate in an exclusive environment as well as in mixed traffic environment. Capacity is an important parameter to estimate facility and facility performance. Therefore to evaluate the same, Ahmedabad BRT facility was chosen in present study. On basis of boarding and alighting data, busiest route comprising of both segregated (exclusive environment) and un-segregated (mixed traffic environment) stretch was selected. For the estimation of capacity, empirical method was adopted. Bus lane capacity for segregated stretch and un-segregated stretch was estimated as 213 buses/hr and 101 buses/hr respectively. The overall capacity value of hybrid BRT facility was minimum of the two i.e. 101 buses/hr. After estimating capacity so obtained, the effect of mixed traffic environment on overall facility capacity was observed and conclusions were drawn. Also the sensitivity of capacity under the influence of failure and dwell time on Bus lane capacity was investigated. Further, in this study an attempt has been made to estimate capacity using conventional Greenshield Model on a mid-block section. Following this, the results of two approaches namely, empirical model capacity and capacity using Greenshield model were compared. The capacity obtained at mid-block section of segregated stretch was over estimated by 36.15% being 290 buses/hr as compared to the empirical method (213 buses/hr).