Public bus services versus congestion and pollution in Lima and Callao

Abstract

This study measures the influence of public bus services on traffic congestion and environmental pollution in Lima and Callao. The effect of the flow of buses on the transportation network is measured by way of a dynamic traffic assignment program, Dynasmart. The database is constructed on the basis of the 2005-2025 Master Plan. To this end, the transportation network is verified using Google Earth, and field measurements of capacity, speed, and volume- relay functions to describe traffic congestion are used. The flow of buses is calculated using the Emme3 program. Origin-destination matrices are calculated for each hour based on the 24-hour origindestination matrix from the Master Plan. In the case of congestion, both the exact and the maximum influence of the flow of buses are measured, and the case of segregating a traffic lane for a Rapid Bus System—a much-discussed topic—is also considered. In the case of pollution, the exact influence of the flow of buses is used to measure fuel consumption and pollutant emissions for the option of reducing public bus services as well as a further five options, including the implementation of a Rapid Bus System featuring gas-powered buses. It is found that halving the size of the bus fleet increases the speed of the transportation network by between 2 and 7% per day, and between 9 and 14% until 11 am, and yields 46% of the benefits of promoting clean fuels and inspection and maintenance; that is, that this measure is of limited worth in reducing congestion, and should not be considered a priority means of alleviating pollution.