Economic Evaluation of Trends in Travel Time Reliability in Road Transport

This study aimed to demonstrate that travel time reliability and road network robustness from the user’s perspective could be measured with the use of detailed traffic data and according to a definition proposed by international experts. These measurements can be used to describe and explain the trend of travel time reliability and to describe the trend of extreme travel time delays (or nonrecurrent congestion). In the Netherlands, the trend of travel time unreliability increased until 2008 but was followed by a decline in subsequent years until 2011. Socio economic factors, such as population growth and employment, appeared to be the underlying factors for the increase in travel time unreliability. Serving as a counterbalance were various transport policy measures, such as the addition of lanes, traffic management, and speed limitation and control, which vere implemented primarily during the years 2009 to 2012. Finally, the study demonstrated how the volume of travel time reliability could be used as a component for the cost—benefit analyses of
adding infrastructure and for calculating the social costs of travel time unreliability for users of the main trunk road network.