Institute for Transport Studies (ITS)

Modelling and Valuing Reliability and Punctuality

"As incomes rise, so people and businesses want to use transport more. Born of this economic success, congestion and reliability problems arise when demand starts to outstrip available capacity. Unless policy responds, these transport impacts will impose increasing costs on business and damage the UK’s quality of life." - (HM Treasury, 2006)

Unexpected delays can be stressful to us all, whether we are individuals travelling by car or train, or a business delivering or receiving goods. For important business meetings, when picking up young children or for time-critical deliveries, we build in extra ‘slack-time’ which has negative personal and economic impacts. As our road and rail transport systems reach capacity, so the prevalence of unexpected delays only increases. Governments around the world have begun to appreciate the potential benefits to society and the economy of better understanding this phenomenon, in order to design more robust future transport systems.

We take a leading role in developing the methods and empirical understanding of the issues of reliability and resilience. We have contributed to methods and the empirical evidence base on issues such as:

  • The value of reliability, to both passengers and freight operators
  • The impact of changes in reliability on travel demand
  • The impact of changes in reliability on network performance

We have also applied these methods in studies commissioned by key stakeholders such as:

  • The UK Department for Transport (e.g. on rail and multi-modal reliability);
  • The Highways Agency (e.g. on the M6 toll, on Public Service Agreement reliability targets);
  • The Office of Rail Regulation (e.g. on the 2013 revision of the Schedule 8 performance regime);
  • Passenger Demand Forecasting Council (e.g. on the 2013 revision of guidance on punctuality within the Passenger Demand Forecasting Handbook).  

Recent research outputs:

Watling, D.P. & Balijepalli, C. (2012) A method to assess demand growth vulnerability on road network links. Transportation Research Part A, 46, pp772-789.

De Jong, G., Kouwenhoven, M., Kroes, E.P., Rietveld, P., and Warffemius, P. (2009) Preliminary monetary values for the reliability of travel times in freight transport. European Journal of Transport and Infrastructure Research, 9, pp83-99.

Batley, R., Dargay, J., and Wardman, M. (2010) The impact of lateness and reliability on passenger rail demand. Transportation Research Part E: Logistics and Transportation Review, 47 (1), pp61-72.

Batley, R. and Ibáñez, J.N. (2013) Randomness in preference orderings, outcomes and attribute tastes: An application to journey time risk. Journal of Choice Modelling, 5 (3), pp157-175.

For further information, please contact: Professor David Watling or Professor Gerard De Jong