Achilles’ heel: level crossingsFeb 21st, 2011 | Category: Articles, Current Issue ID, February11, Policies & Strategies
In spite of the best safety precautions, level crossings remain a weak point. Generally, operations are fully automatic. In the event of a malfunction, the fail-safe principle applies. The safety system takes over and prevents a level crossing from opening by mistake. Nevertheless, most incidents still occur at level crossings. Car driver carelessness or recklessness are usually to be blamed. That it why, where possible, it is recommended to replace level crossings with tunnels or bridges.
Each year people die in accidents involving road vehicles colliding with trains at level crossings. 95% of these fatalities are attributed to faults by the road vehicle driver who doesn’t observe signalling. Despite this, society labels most fatal accidents at level crossings as a rail problem.
So a significant risk to the safe operation of the rail network is in fact only a small element of the overall road safety issue. What can we do to redress this uneven balance?
In many countries, level crossings on less important roads and railway lines are often “open” or “uncontrolled”, sometimes with warning lights or bells to warn of approaching trains. Another critical point is the lack of projects in which rail and road operators are jointly involved.
To reduce the impacts due to accident operational consequences at level crossing and to increase safety and human awareness is important to introduce new technologies in level crossings operational management, but high safety requirements together with high railway standards are presently hindering technological upgrade of level crossings.
In order to calculate the risks of failure and hence the change in failure risk when new technology is introduced, it is necessary to carry out a comprehensive physical decomposition of the system in question.
Moreover it is not possible to quantify the relationship between the cost of new technologies and the risk reduction that their introduction involves. This is mainly due to unavailability of a statistical base and the missing of data standardisation as well as inputs for the required evaluations.
Low cost level crossing solutions
A significant part of the technology oriented rail side projects is dedicated to the investigation of low cost solutions applicable especially to level crossings with low traffic conditions (road and rail). The aim of these projects is to reduce the contemporary relatively high number of accidents occurring on passive level crossings equipped only with St. Andrew‘s cross. Such technological developments are in their testing and evaluation phase in Austria (ISIS), Switzerland (Micro) and France (SAL0).
A common aspect of the low cost level crossing solutions is the assignment of the responsibility to the road user in the case of an equipment failure. Such a state must be clearly visualized when new technologies are installed.
The projects mentioned above assume the use of technology with lowered level of safety (lower than SIL4, required for most of conventional level crossing safety systems). As shown by the first results of the tests the proposed solutions are able to fulfil the high reliability requirements. It is the task of a risk analysis to confirm the safety benefit of the practical introduction of these solutions. It is expected that by considering the low traffic volumes specific for the targeted level crossing types the results of these research projects can practically be used.
Who will assume responsibility?
Level crossings safety depends on several parameters (signalling system, operational condition, traffic flow). It’s not possible to propose “the best solution” so that Safer European Level Crossing Appraisal and Technology (SELCAT) and UIC propose, through a conducted study, two different scenarios to be investigated – rural area and secondary line with low traffic (rail and road) and urban and suburban area main railway line with high traffic. For rural area and secondary line with low traffic (rail and road) warning system to road users has to be preferred. This also raises questions that need answers and more commitment in reducing the number of level crossings accidents. For example, what device to be used (camera, radar, laser-scan), what function has to be developed? (reduce the waiting time in queue, in-cab information to train driver, fixed signalling), what happens when a device detects an object (emergency brake, operational brake) and most important, what happens when a detecting device fails? The specialized railway industry develop solutions to increase level crossings safety, but in order to achieve these goals, it is necessary for rail or road authorities to start implementing projects.
[ by Elena Ilie ]