Overview / Background
Currently in most countries the evaluation of the effectiveness of road safety measures is not part of a routine within the road safety programme, with a dedicated budget. Even in countries that perform road safety measures assessments, the evaluation is usually limited to infrastructure and enforcement measures while the evaluation of entire road safety programmes is even more rare. To improve Road Infrastructures Safety Management the road authorities and the road designers need prediction tools allowing them to analyze the potential safety issues, to identify safety improvements and to estimate the potential effect of those improvements in terms of crash reduction.
The PRACT Project (Predicting Road ACcidents - a Transferable methodology across Europe) aims at developing a European accident prediction model structure that could be applied to different European road networks with proper calibration. The core principles behind the PRACT project structure are that:
- the idea that a unique Accident Prediction Model (APM) model and unique set of Crash Modification Factors (CMFs) can actually be developed, valid for all Europe and for all the different type of networks of motorways and higher ranked rural roads, is unrealistic;
- the development of a specific APM model and a set of CMFs based on local data is extremely time consuming and expensive and requires data and experience that most road administrations do not have;
- the development of “local” CMFs only based on historical local data prevents the possibility of evaluating the effectiveness of new technologies.
The basic assumption on which the PRACT project is therefore built is that APMs and CMFs can be transferred to conditions different from the ones for which they have been developed if selected based on scientifically valid criteria and adapted to local condition based on historical crash data.
The PRACT project is aimed at addressing these issues by developing a practical guideline and a user friendly tool that will allow the different road administrations to:
- adapt the basic APM function to local conditions based on historical data;
- identify the CMFs that could be relevant for the specific application;
- verify if the selected CMFs are transferable to the specific condition;
- apply the calibrated model to the specific location to be analysed.
As far as different countries, as well as different road authorities within a country, have different level of expertise and different data availability, the system will be structured with different possible calibration levels ranging from a total lack of historical data (in this case the user will be proposed the most suitable set of calibration parameters among the ones that will obtained within the PRACT project with the available datasets) to situations where crash data, traffic data and geometric data are all available and the system could allow also for the calibration of key CMFs.
An important outcome of the PRACT Project will also be the establishment of a European AMF and CMF web repository with an open access database of Accidents Prediction Models and Crash Modification Factors and hints for their application and transferability on the European road networks.
Predicting Road ACcidents - a Transferable methodology across Europe
Francesca La Torre
Università di Firenze
Via Santa Marta 3, 50139 Firenze, Italy
Planned End date:
PRACT project is part of the CEDR Transnational Road Research Programme "Safety" funded by Germany, Ireland, UK and Netherlands