Estimating Capacity of Hybrid Bus Rapid Transit Corridor

The main objective of this study is to estimate the capacity of hybrid bus rapid transit (BRT) corridor. By the term hybrid BRT corridor in context to this study, we mean a corridor in which buses have to operate in an exclusive environment as well as in a mixed traffic environment. Capacity is an important parameter to estimate corridor and system performance. Therefore to evaluate the same, Ahmedabad BRT system was chosen in the present study. On the basis of boarding alighting data, the busiest route comprising both segregated (exclusive environment) and unsegregated (mixed traffic environment) stretch was selected. For estimating the capacity, an empirical method was adopted. Bus lane capacity for segregated stretch and unsegregated stretch was estimated as 243 buses/h and 101 buses/h respectively. The overall capacity value of hybrid BRT corridor was minimum of the two, i.e. 101 buses/h. After estimating the capacity so obtained, the effect of mixed traffic environment on overall corridor capacity was observed.

Further, an attempt was 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 the segregated stretch was overestimated by 19.34% or 290 buses/h compared to that obtained using empirical method (243 buses/h).