Project: Development of INCA to incorporate Inter Urban single carriageways

Reference: R180A

Last update: 15/08/2013 15:58:12


This project will deliver a set of models in a report that will enable users to model travel time reliability


. Produce a specification and develop algorithms and methods that enable INCA to accommodate analysis for single carriageways. The specification for the algorithm will include data input, the form of the outputs and reports, basic checks and error traps. The algorithm should be designed to allow for incidents on single carriageway roads to be modelled effectively.
. Make improvement to the DTDV calculation in INCA by estimating travel time variability as a function of traffic flows and journey time on motorways, inter-urban roads and rural or inter-urban single carriageways. A similar approach has already been developed for urban roads (DfT, 2004) and in Sweden (ETC, 2006). This work could use the journey time data in HATRIS. Other database such as ITIS could be used.
. Explore the availability for data on single carriageway incidents required to generate parameters for single carriageways similar to that of motorways in INCA in the medium to long term. This would need to address the following: junction related incidents; shuttle working issues; and the wide variety of standards of single carriageway roads.


This project aims to improve our understanding of the impact of congestion on travel time reliability as the level of demand for road space interacts with the level of service provided. The project would give us improved methodology to better assess and appraise reliability as a result of interventions. Better informed methods for modelling reliability would result in better forecast measures of congestion agreed as PSA targets.


Mott MacDonald
Devon House, 12-15 Dartmouth Street, London, SW1H 9BL
20 7340 2250

Contract details

Cost to the Department: £130,870.00

Actual start date: 02 February 2007

Expected completion date: 28 February 2008