Standardization of logic for a constant warning time control at automatic level crossings

In Japan, there are a lot of high-density railway lines and along the line the long warning time at level crossings has become a social problem.Particularly, about 600 level crossings have a warning time of more than 40 minutes per hour in rush hour.As a result, the traffic of cars and pedestrians is disturbed for a long time.Eliminating level crossings by making overhead crossings has been attempted, but a lot of time and costs are necessary.Therefore, it is an urgent problem to shorten the warning time for such level crossings.Although a constant warning time control for level crossings has been widely adopted at JR East as a countermeasure against the length of time that the level crossing barrier is closed, it requires a lot of hard work on its design and construction as well as testing because its control logic differs in level crossings.In order to cope with this situation, we employed a new train counting sequence, employing two types of counting logic to replace the track circuits.To realize this logic, we only need two starting points and one stopping point.When a train enters one of the two starting points, the train is counted according to the corresponding type.When the train leaves the stopping point, it is subtracted.Thus, we have achieved a train recognition sequence without track circuits.We can apply this simple sequence to all types of automatic level crossings.We are going to incorporate this logic in PLC (programmable logic controller) as a new microelectronic level crossing controller.It is expected to become a product after passing the field test.By using our development, it is expected to reduce the time for design, construction and testing.Furthermore, it is also expected to reduce the number of relays, which leads to a reduction in cost.By the above-mentioned Computers in Railways XIV 87