Overview
The standard SN 671 520 is based to a large extent on directives of Swiss Federal Railways SBB, which were not implemented in the legal regulations (AB-EBV). Therefore the corresponding regulations of the standard have no longer been applied for several years. Safety measures have been established on an individual case basis with the imminent risk of disparity. The harmonization with the AB-EBV is urgent.
Accidents with participation of low speed traffic and motor vehicle in connection with roads meeting or running close to railways are still comparatively frequent considering the very high safety level of the Swiss road network.
The project has following objectives:
- Evaluation of safety level achieved by previously applied safety measures concerning roads meeting or running close to railways(excl. level crossings)
- Evaluation of safety level achieved in Switzerland in comparison to the international (mainly European) safety standard
- Evaluation of the feasibility and efficiency of the regulations in the European environment
- Evaluation of safety measures appropriate for Swiss conditions concerning roads meeting or running close to railways
- Identification of the requirements for the revision or the amendment respectively of the regulation of standard SN 671 520 in terms of safety technology and draft of the revised standard.
The definitions and the requirements for arrangement of vehicle restraint systems of the standard "Passive protection in roadways" (SN 640 566) are a basis for the project.
In order to obtain supplementary information interviews or hearings are conducted and evaluated at selected road administrations, traffic police authorities and railway companies and cities with tram operation.
Changes in the European railways rules in terms of passive safety of road space and in terms of standardization "lines and geometric standard profile" regarding authoritative guidelines are evaluated.
The relevant rules are checked for compliance with sustainability objectives according DETEC specifications.
The methodology applied in relation to the new guidelines on the parallel guide is tested in terms of transferability to Swiss conditions and the suitability for a possible implementation in the Swiss road network. Here, the risk is related optimization potential - particularly with respect to existing protective devices - in the foreground. This potential is estimated on the basis of an update of the existing evaluations of the Swiss accident statistics and risk analysis.
Sustainability goals according DETEC specifications are also an important parts of the project. The elaboration of measures proposals carried out in compliance with the instructions for checking the VSS standards on safety aspects with checklist.
Funding
Results
Decisive Aspects
The following aspects were identified to be decisive with regard to the revision of the standard:
- The risk evaluation methodology underlying the regulations of Great Britain, the Netherlands, France as well as the Highway Safety manual of the USA must be considered in the draft of the revised standard in terms of a harmonization with international regulations.
- For different reasons the basic data set is not sufficient to determine the risk parameters completely in a statistic sense. Therefore, the remaining gaps are to be closed by expert judgement.
Risk-based Methodology
In the context of the evaluated risk-based methodology the required safety distances and safety measures are determined by 14 risk factors characterizing type and volume of traffic as well as site specific hazards.
The value for the total risk caused by the accidental obstruction of the railway by road vehicles is calculated by multiplying all risk factors, whereas for calculating the partial risk caused by the accidental obstruction of the railway by truck load only a part of these factors is taken into account.
The limit for acceptable risk as well as for unacceptable risk is determined based on the evaluation of case studies concerning typical hazardous situations.
Suggestions for the revision of the standard SN 671 520
Based on the identified need for a revision and the established updated risk-based methodology a draft was developed for a revised standard SN 671 520.
The resulting safety measures elaborated on the basis of the draft comply in every regard with the level of safety prescribed by the regulatory authorities during the last years.
Other results
Guidelines for the optimal and coordinated with the European environment risk-based definition of the security measures in the parallel guide and at the confluence of rail and road.
Contribution to improving the safety of road and rail traffic and optimize the use of financial resources by simplifying planning processes and by a risk-based, and thus cost-effective planning and implementation of security measures. Prevention of interruptions in public transport by road errant vehicles.