Problems associated with warning generation at railway crossings

Aim. To study the process of operation of the existing level crossing devices. To examine a detailed barrier operation algorithm that takes into account the proper operation of each component. The existing level crossing protection systems use simplified operation algorithms. To focus on the process of crossing warning generation when a train enters the warning section. To examine in detail the work of operators who identify the distance to a vehicle and, consequently, the barrier activation time. That will allow adjusting the barrier activation time and, consequently, reduce the rolling stock downtime. Methods . The paper suggests a method that involves continuously measuring the vibration displacements of the rails at the crossing using an accelerometer. By continuously measuring the values of vibration velocity (V) and vibration acceleration (a) at the boundary of a crossing, a set of measured values Vi and ai is generated. These values are used for making a system of equations for the train location coordinate, whose right part is equated to the values of the train coordinates. By solving the system of train coordinate equations using the values of vibration velocity (V) and vibration acceleration (a) at the boundary of a crossing at the approach of a train, the coordinate of the vehicle can be defined at specific points in time. Consequently, the speed and nature of its movement can be identified throughout the warning section. Out of the obtained values, the time of the train’s head clearing the crossing can be identified. By comparing the estimated barrier activation time with the time derived from the nature of a train’s movement, the moment of crossing barrier activation can be identified. Results . The study showed that the existing level crossing warning systems deployed within stations normally activate barriers in advance. That may cause motor vehicles to spend excessive amounts of time before a crossing. If the length of the approach section is fixed, the actual warning time is inversely proportional to the train’s speed and may significantly exceed the minimum required time. Excessive warning time may have negative consequences, which requires a solution. If a crossing is regularly closed for long periods of time, drivers will be attempting to cross faster once the restrictive signal has turned on, which may lead to accidents, train-to-motor vehicle collisions. Should data on the actual time of a train’s arrival to a crossing be available, the time spent by motor vehicles at closed crossings will be able to be reduced down to the estimated closing time and the time it takes for the train to clear the crossing. The average train speed in the Russian Federation is 35.7 km/h [1], while warnings are calculated for the top speed. Conclusion. The time spent by vehicles before a barrier can be reduced about 3 to 4 times. Consequently, the number of accidents at crossings can be reduced as well.