Traffic Forecasts under Uncertainty and Capacity Constraints

Recent empirical evidence suggests that long-term traffic predictions are subject to high levels of uncertainty. This paper quantifies uncertainty in traffic forecasts for the tolled motorway network in Spain by estimating a demand model using a panel data set covering 67 tolled motorway sections between 1980-2008. Uncertainty is quantified in the form of a confidence interval for the traffic forecast that includes both model uncertainty and input uncertainty. A stochastic simulation process based on bootstrapping techniques is used. The authors propose a new methodology to account for capacity constraints in long-term traffic forecasts. The methodology involves a dynamic model in which the speed of adjustment is related to the ratio between the actual traffic flow and the maximum capacity of the motorway. The proposed methodology is applied to a specific public policy to suppress the toll on a certain motorway section before the concession expires. In this case, the government had to compensate the private motorway concessionaire for the revenue foregone up to the end of the concession period. A point estimate for the present value of the foregone revenue is presented as if the result were certain. A set of confidence intervals at different levels of significance that account for the variance of the forecasting error is then presented.

• Record URL:
  https://doi.org/10.1007/s11116-011-9325-1
• Availability:
  • Find a library where document is available. Order URL: http://worldcat.org/issn/00494488
• Authors:
  • Matas, Anna
  • Raymond, Josep-LLuis
  • Ruiz, Adriana
• Publication Date: 2012-1

Language

• English

Media Info

• Media Type: Print
• Features: Appendices; Figures; References; Tables;
• Pagination: pp 1-17
• Serial:
  • Transportation
  • Volume: 39
  • Issue Number: 1
  • Publisher: Springer
  • ISSN: 0049-4488
  • EISSN: 1572-9435
  • Serial URL: http://link.springer.com/journal/11116

Subject/Index Terms

• TRT Terms: Highway capacity; Methodology; Toll roads; Traffic forecasting; Traffic simulation; Travel demand; Uncertainty
• Geographic Terms: Spain
• Subject Areas: Highways; Planning and Forecasting; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 01470822
• Record Type: Publication
• Files: TRIS
• Created Date: Jan 29 2013 9:20AM