Evaluation of new human-centred low-cost measures. Deliverable D2.4 of the SAFER-LC project

Kurzfassung

This deliverable describes the methods applied and the results achieved during the second phase of Task 2.3 in the SAFER-LC project: the evaluation of new human-centred low-cost measures to improve safety at level crossings (LCs). The European project SAFER-LC – Safer level crossing by integrating and optimizing road-rail infrastructure management and design – aimed to improve safety in road and rail transport by minimising the risk of LC accidents, focusing on both technical solutions and human processes. Within the project, the objective of Work Package 2 (WP2) was to enhance the safety performance of level crossing infrastructures from a human-factors perspective, making them more self-explaining and forgiving. Task 2.3 specifically aimed to design human-centred low-cost countermeasures to enhance the safety of current LC infrastructures and, in a later step, to evaluate these countermeasure designs from a human-factors perspective. This objective was driven by the insights of the major role that road user behavior plays in accidents at level crossings and the need for safety measures to be affordable to enable their application to a large number of crossings and the achievement of tangible safety effects. The activities in the design of countermeasures were performed in the first phase of task 2.3 from May 2017 to October 2018. They resulted in a list of 89 reviewed LC safety measures, of which 36 measures were for use at passive LCs, 29 for LCs with barriers, and 24 for use at all kinds of LCs. For the purpose of evaluation, Task 2.3 referred to two main inputs from other tasks within SAFER-LC: the human factors methodological framework developed in Task 2.2 and the pilot tests of innovative LC safety measures performed in Work Package 4 (WP4). The human factors methodological framework was developed to define what aspects of human behavior should be considered when trying to assess the suitability of a LC safety measure. It also defined important context variables that influence this suitability, including environmental factors such as LC type, layout, weather, traffic etc. as well as the issue of acceptance by different stakeholders. The methodological framework is based on sociotechnical systems theory, relevant models of human cognition and behavior, and analytical tools and empirical approaches from related research projects. Its development resulted in the definition of three sets of criteria important to the human factors assessment of a given LC safety measure. To facilitate and structure the application of the framework, a human factors assessment tool (HFAT) was developed. Its core is a survey comprising checklists and forms to assess the three sets of criteria defined. The tool helps to collect and systemize relevant information on a given LC safety measure in order to enable a reasoned estimation of its effects in road user behavior, user experience and social perception. The pilot tests in WP4 involved two kinds of tests. One kind focused on demonstrating the feasibility of technical solutions to improve LC safety. The other one was concerned with the effects of LC safety measures on road user behavior. This included two simulator studies of infrastructural safety measures, an online survey based on videos of a train-mounted countermeasure in a real rail environment, a field test of an in-vehicle LC proximity warning, and a field test of two infrastructural measures. Based on the results of these tests, the pilot site leaders used the HFAT to assess the piloted measures from a human-factors perspective. Using the HFAT enabled the presentation of the results in a common format, although the input studies used different methods and measured different indicators. The LC safety measures evaluated in this way were: blinking lights for the locomotive front, coloured road markings on approach to the LC, in-vehicle proximity warning, rings upstream of the LC, traffic light, blinking amber light with train symbol, funnel effect pylons, message , “<-- Is a train coming? -->” written on road, peripheral blinking lights, rumble strips, sign “<-- Is a train coming? -->”, and speed bump and flashing posts. The four measures assessed to most facilitate safe road user behavior in the HFAT evaluation were the blinking lights for the locomotive front, the two in-vehicle proximity warnings, and the peripheral blinking lights. Minding the evidence collected in the HFAT, this assessment is rather certain for the two measures involving blinking lights, and more tentative for the in-vehicle proximity warnings. Stakeholder acceptance and user trust are expected to be sufficient to allow for successful implementation of these measures, minding the principles of stakeholder participation and user-friendly design. Two measures scored particularly low on the assessment of behavioral safety effects: the funnel effect pylons and the message “<-- Is a train coming? -->” on the road. Both assessments are tentative, as the findings from the pilot are the only evidence available by now. Due to the low expected efficacy, acceptance and trust values were not considered in these cases. The seven remaining measures were attested a medium effectivity on the facilitation of safe behavior. These assessments are more certain for the rumble strips and the sign “<-- Is a train coming? -->”, and remain tentative for the coloured road markings on approach to LC, the rings upstream of the LC, the traffic light, the blinking amber light with a train symbol, and the speed bumps and flashing posts due to the limited availability of evidence. Based on the acceptance and trust values obtained with the HFAT, successful implementation appears possible for most of these measures. Some difficulty in implementation is expected based on the acceptance assessment for the coloured road markings on approach to LC, the rings upstream of the LC, and the funnel effect pylons. Beyond its use as a tool to guide and evaluate empirical research on LC safety, the HFAT can also be used by road and railway transport stakeholders as a checklist to support the consideration of human factors aspects in the evaluation of LC safety measures. Using the HFAT in this function can help to assess the suitability of a LC safety measure to different railway environments and user requirements and to avoid efficacy barriers, by considering the important issues of acceptance and social perception of road users and other stakeholders. The results obtained in SAFER-LC Task 2.3, the design and evaluation of human-centered low-cost measures to improve LC safety, will be used as one main input in the implementation of the SAFER-LC toolbox, a web-based tool for anyone concerned with LC safety. The toolbox is conceived to be a guide to best practice that integrates all the recommendations, promising interventions, and specifications developed during the project with the empirical evidence collected from the scientific literature and the pilot tests. The toolbox will be accessible free of charge at the end of the project and will continue to be maintained, updated and improved by the International Union of Railways (UIC) for the benefit of the road- and railway-safety community.