Application of IHSDM Design Consistency Module and UK Operating Speed Prediction Model: A Case Study in the UK

Operating speed and design consistency have been agreed as the two critical measures of highway design evaluation, and could help researchers to study the contributors of traffic accident and black-spots on roads. In the UK, Hashim has developed the most recently model since the first operating speed prediction model published in 1989. Comparably, much more researches have been conducted in the USA, and a lot of achievements have been received. The Interactive Highway Safety Design Model (IHSDM) is a suite of evaluation tools for highway geometric design. Both of the two models are mainly focused on two-lane rural highways which also dominate the primary road classification in the UK. The major goals of this research are to find effectiveness of the highway design evaluation solution- IHSDM applying on the UK roads, as well as the further possible developments of model developed by Hashim. The background of the two models has been investigated; furthermore, they have been implemented on carriageways to systematically evaluate their practical feasibility in the UK, especially for IHSDM. The comparisons of predicted operating speeds with collected speeds, as well as the appraisal of the results with traffic accident data both have been achieved. Finally the further tasks that are required to make IHSDM appropriate for the UK conditions are recommended, including calibration of IHSDM Design Consistency Module to local situations, verification of highway alignment data input procedures of IHSDM; moreover, based on the results of applying the Hashim's model, the constructive suggestions for the further development have been also presented in this report.