Ch. Ravi Sekhar

Modeling travel time of car with varying demand on an urban midblock section

ABSTRACT The present study analyzes the stochastic nature of travel time distribution under the uncertainty of traffic volume and the proportion of cars in the traffic stream. Stochastic response surface method (SRSM) is adopted for modeling the travel time variation under the influence of traffic composition and traffic volume. This model is applied to an uninterrupted urban arterial corridor of 1.7 km length in New Delhi. Video graphic data were collected for 2 days during morning hours between 8 AM and 12 noon and evening hours of 3–7 PM. License plate matching technique was used for measuring the travel time in the study area. This study focused on travel time variation of cars with varying traffic volume and proportion of car in the traffic stream. Linear regression analysis was carried out initially to know the functional relation and significance relation between the input and output variables, and then SRSM analysis was performed. Artificial neural network (ANN) is also considered to map the relation among travel time, traffic volume and composition of traffic stream. A comparative evaluation is made among ANN, SRSM and regression analysis. Results indicate that apart from traffic volume, the influence of car population is more on travel time variation than motorized two-wheelers. It is attributed to the smaller size and comparability better operating condition of motorized two-wheelers. Also, the ANN and SRSM models are more efficient for analyzing the stochastic relation between the response and uncertain explanatory variable than the regression model.

Examining Bus Lost Time Dynamics for a Bus Rapid Transit Station

Bus Rapid Transit (BRT) systems are considered to be the most effective alternative for solving urban transportation problems for both developed and developing countries. The conventional approach to estimate dwell time (DT) is based on traditional DT models derived for normal bus stops, but not for modern BRT stations. BRT stations are different from bus stops in terms of length of platform, multiple loading areas, and number of passengers handled. Therefore, understanding dwell time dynamics, including the recently-introduced component of Bus Lost Time (BLT), is important to improve the operations of BRT systems. This research introduces various possible scenarios of alighting and boarding using video data collected at the Shivranjini BRT station in Ahmedabad, India. In total, 877 observations of BLT and DT were extracted from 17 hours of video data recorded for one full-service time of the day. The possibility of BLT occurrence was examined and explained with the help of conceptual line diagrams, and the probability distribution of BLT was fitted for two loading area platforms by considering 401 observations from the BRT platform video data of the entire service period. A comparative evaluation was made between observed and estimated BLT values. This study estimated station capacities before and after, including BLT as a DT component to observe the effect of BLT on BRT stop capacity. It was observed from the results that including BLT in dwell time reduced BRT capacity by 11%. This study provides ready-touse BLT values for correct estimation of dwell time, thus improving accurate estimation of BRT station capacity.

A review of bus rapid transit implementation in India

Abstract Between 2008 and 2015, bus rapid transit system (BRTS) in India increased its implementation from two cities to eight cities with a significant increase in total ridership. This paper attempts to give a detailed review of BRTS implementation in cities of India. This is a systematic effort that could inform readers about the current system and network characteristics of Indian BRTS. Different system and corridor characteristics including off board and on board ticketing systems are adopted in India. Gross cost revenue collection model is adopted by almost all special purpose vehicle (SPV) companies developed to manage BRT systems. A variety of carriageway concept designs for BRTS are implemented in these cities considering a right of way of 22, 24, 30, 32, 40, 45, 60 meters respectively. Out of the eight cities, Ahmedabad has almost 30% of the total fleet size. In terms of regulatory context, SPV companies are formed in almost all eight cities after observing Ahmedabad BRT success. Documentation of these operating systems shall provide a sound database to planners and decision makers actively involved with BRT system implementation in developing countries.