Modelling induced travel demand in a developing country: evidence from Dhaka, Bangladesh

Abstract

This research evaluates induced travel demand with the construction of transport infrastructure, using flyovers as a case study. Induced travel demand is defined as an increase in travel as a result of any increase in the capacity of a transportation system. However, relatively little is known about the induced travel demand effects of flyover infrastructure in developing countries.This research endeavours to answer the question of whether the construction of flyover induces travel kilometers or induced trips. The objectives of this research are to estimate average travel distance and trip frequencies based on socio-economic and travel characteristics of flyover and non-flyover users; to measure induced travel kilometres and induced trips caused by construction of flyovers; and to model induced travel kilometres and induced trips. Using purposive sampling techniques, both an intercept survey and online questionnaire were conducted to collect the data from 1060 vehicle users who used flyover and non-flyover roads in Dhaka.An independent samples t-test estimated that there is a statistically significant difference between flyover and non-flyover users. Induced travel kilometres and induced trips made by these two groups are also reported. Using a linear multiple regression model, the study found that the number of trip frequency of flyover users is increased by 0.350 owing to a one-minute savings in their travel time. The findings of this research contribute to guide policies that include the effects of induced travel demand when constructing new roadway facilities, particularly in Dhaka and other cities in developing countries.