New Findings in the Netherlands about Induced Demand and the Benefits of New Road Infrastructure

The increase in traffic volume that arises after opening of new road infrastructure, is often attributed to ‘induced demand’. The objective of this study is to provide empirically derived insights in this phenomenon, in the amount of induced demand and in the benefits that adding road infrastructure has for users. Based on multivariate analyses of detailed data in The Netherlands from 2000-2012, it is concluded that the amount of induced demand in total is relatively low and that the relatively large increase in traffic volume during peak hours on roads that were congested before adding lanes mainly has been caused by shifts in route and departure time. The benefits of the new infrastructure for users have been calculated in terms of savings of travel time and travel time reliability. Implications for cost-benefit analyses of road investments have been reviewed.