Highways England Trip Information System Verification
Nick Corby, Highways England, Stephen Rutherford, Jacobs, Timothy McHugh, Telefonica
The paper will describe how the Trip Information System is validated and applied to a model.
This paper will report the verification and validation of the Trip Information System, a mobile phone based trip database developed for Highways England by Jacobs and Telefonica. The Trip Information System is the first large-scale application of mobile phone data for transportation in the United Kingdom. The validation and verification process calls for a series of tests against (i) third party data sources such as census information and (ii) a transport model built using traditional road side interviews, so that the quality of the data output can be validated and we can provide the final phase of the project; the supply of demand data for Highways England/Department for Transport projects right across the country. This process also provides a feedback loop to help inform revisions/upgrades to the complex methodology that takes data from mobile phones and applies a consecutive series of algorithms and processes to rectify the data into anonymised demand data for model input.
There are many challenges that need to be overcome in the validation process. Most data sources are based on surveys and models that cannot be considered as providing an ‘absolute’ source of truth, so verification needs and intelligent understanding of their application and their limitations. Other challenges include (i) the lack of freight trips in most surveys compared with them appearing in mobile data, (ii) the comparison of variables across different units, e.g. trips vs population, and (iii) the rectification of rail demand when comparing stations with line route segments.
The first part of the paper considers the validation steps undertaken for the Trip Information System, the data sources and methodologies employed; including how this fed back into the methodology. The second part of this paper covers the application of the Trip Information System matrices on a transport model to simulate modelling practice. These findings have produced the recommendations for (i) improving the Trip Information System methodology prior to industry release, and (ii) key components of the user guidance in advising on the application of the data to future model construction.
Association for European Transport