[membership_content level=”basic”]

When evaluating level crossings, the initial step involves determining if there are feasible alternatives to installing a level crossing. This assessment should ideally occur during the planning phase of a level crossing within the context of an integrated system approach. Although new level crossing proposals are uncommon, projects that revive old railway lines might suggest reestablishing previously existing level crossings. In the planning stages of a new or restored railway project, there tends to be more room for maneuvering and exploring alternative solutions.

It is essential for risk evaluations to always contemplate the possibility of closing an existing level crossing as a viable option. Nonetheless, it’s acknowledged that numerous factors must be considered, including the legalities surrounding the closure of public pathways. While the cost implications of alternatives are a consideration, the practicality of these alternatives must also be evaluated. For instance, level crossings are frequently situated in densely populated areas where bridge construction could significantly disrupt residents. Community sentiments may vary, with some in favor or opposing a level crossing. Therefore, effective communication among the railway authorities, local government, and stakeholders like users and property owners is crucial.

The main hazards/risks taken into consideration are the following:

• Collision risk
• Equipment failure;
• Human error;
• Visibility issues;
• Train speed and frequency;
• Inadequate user awareness or compliance.

Addressing these hazards requires engineering solutions, public education, strict enforcement of crossing rules, and ongoing safety equipment maintenance and testing. These risks also heavily depend on the type of level crossing protection, as defined in Table 1.

Table 1. Hazards/risks by level crossing protection type

Risk acceptance is based on principles of each railway administration’s experiences with its systems. In Europe, the following principles are most often applied:

• ALARP (As Low As Reasonably Practicable);
• GAMAB (Globalement Au Moins Aussi Bon);
• MEM (Minimum Endogenous Mortality).

ALARP is a principle accepted in England and some other highly developed countries, and it predicts that the level of risk should be as low as it is practically possible to achieve. There are three different target groups of individuals who are exposed to the risk of the level crossing system (employees, passengers, population, etc). For each target group, there is an upper limit of acceptable risk (for female passengers, the risk must not be higher than10^-4 deaths per road user per year), and the definition of a lower limit (risk lower than 10^-6 deaths per road user per year (for passengers)) is always acceptable. If the determined risk level is within these limits, some methods to reduce the risk level can be applied only if it makes economic sense. The application of this criterion requires a previous cost-benefit analysis.

The MEM principle is practiced in Germany and implies the existence of precise statistical data on the number of deaths that occurred at road crossings. The upper limit of acceptable risk is 10^-4 deaths per road user per year.

Practice shows that the most suitable principle for securing level crossings is the GAMAB principle. The GAMAB principle, applied in France, dictates that the new technical system to be installed must provide a level of security equal to or greater than equivalent existing systems.

It is assumed that the level of risk of existing systems can be assessed using statistics. Risk levels can only be compared if the systems have comparable performance and operating conditions. Unfortunately, in recent times, the selection of level crossings has been mostly based on the pressure of daily events. The criterion of urgency is characteristic of systems without strategy.

To determine the danger index P of a level crossing, the following formula can be used:

where we have the following:

• T is the number of trains within 12 hours with higher traffic;
• V Is the number of road vehicles within 12 hours with higher traffic;
• F₁-F₄ are the visibility factors for each direction of the level crossing;
• j is the crossing angle between track and road;
• b is a correcting parameter.

For calculating the visibility factor, both the left and right sides of the visible track, from an observer placed 15 meters away from the closest rail for unpaved roads or placed 30 meters away for paved roads, shall be considered. The formula to calculate visibility factors is:

where we have the following:

• v is the train speed in km/h;
• l_i is the length of the visible track up to a distance equivalent to 5v for each of the 4 directions.

So, if there’s no obstacle, visibility equals 1. Figure 2 shows the visibility factors for all four directions on the level crossing.

[/membership_content]