Forecasting Day to Day Variability on the UK Motorway Network

Reliable journeys’ is one of three key objectives of the United Kingdom (UK) Highways Agency. In order to measure and predict reliability, there is a need to understand variability in travel times. Specifically, day to day variability (DTDV) refers to variations in journey time due to unpredictable changes in demand and random fluctuations in capacity. In other words this is what remains after accounting for all predictable variations (time of day effects, day type effects and seasonal effects) and variability due to incidents. The UK Department for Transport (Dft) recognizes that DTDV should be taken into account when appraising potential benefits of transport schemes or policies. Managed motorway systems such as mandatory variable speed limits and hard shoulder running can provide significant DTDV benefits. DfT commissioned Mott MacDonald to carry out a project to calibrate functions for predicting the DTDV on several road types and to incorporate these into INcident Cost benefit Assessment (INCA) software. INCA calculates delays and travel time variability costs relating to incidents, and the benefits that may arise from remedial measures to reduce their impact. In addition, the transferable DTDV functions that were estimated have the potential to be exploited in other future modeling studies and packages, where forecasts of travel time variability and its reliability impacts are required. This paper describes how DTDV functions were calibrated for several motorway link types. These include three and four lane motorways with hard shoulder, mandatory variable speed limits and three lane motorways with hard-shoulder running.

• Record URL:
  https://aetransport.org/past-etc-papers/conference-papers-pre-2009/conference-papers-2009
• Corporate Authors:

  Association for European Transport (AET)

  1 Vernon Mews, Vernon Street, West Kensington
  London W14 0RL,    
• Authors:
  • Sirivadidurage, Sansaka
  • Gordon, Andrew
  • White, Christopher
  • Watling, David
• Conference:
  • European Transport Conference, 2009
  • Location: Leiden Leeuwenhorst Conference Centre , Netherlands
  • Date: 2009-10-5 to 2009-10-7
• Publication Date: 2009

Language

• English

Media Info

• Media Type: Web
• Features: Figures; References; Tables;
• Pagination: 21p
• Monograph Title: European Transport Conference, 2009 Proceedings

Subject/Index Terms

• TRT Terms: Highway capacity; Road shoulders; Running speed; Traffic congestion; Traffic flow; Traffic forecasting; Traffic incidents; Traffic queuing; Travel time; Variable speed limits
• Uncontrolled Terms: Travel time reliability; Travel time variability
• Geographic Terms: United Kingdom
• Subject Areas: Highways; Operations and Traffic Management; Planning and Forecasting; I72: Traffic and Transport Planning;

Filing Info

• Accession Number: 01344849
• Record Type: Publication
• Files: TRIS
• Created Date: Jul 20 2011 7:24AM