Selecting tram links for priority treatments - The Lorenz Curve approach

Road and public transport authorities often have a difficult task in deciding which road links to select for investment in preferential traffic and public transport measures to improve public transport service performance. This paper presents a new approach which adopts the economic concept of the Lorenz Curve to compare link performance in terms of transit operations as well as weighted passenger volume of travel. The paper explores if, and how, these metrics can be re-interpreted to help with targeting improvements for on-road public transport and priority mitigations. The approach collates operational performance data, in this case link speed and also link public transport travel volume to plot the cumulative distribution of link speed/ridership performance as a curve. Two sets of test applications are presented; on a route level basis and secondly a network level analysis. The network level results present the most powerful results with the Lorenz Curve analysis able to quickly identify links that justify greater attention for preferential treatments since they have the worst 20th percentile of operational performance but the highest 40th percentile of relative link ridership. Mapping shows the problem links to be busy routes leading into the central city. Implications for wider application of these methods are discussed. (C) 2016 Elsevier Ltd. All rights reserved.