In St. Petersburg, trams have taught traffic lights to adjust to their movement. When a tram approaches an intersection, the system reconfigures the traffic light's operation in advance so that the tram can pass without unnecessary delay. Currently, this scheme operates on nine routes and allows Gorelektrotrans to save about 40 million rubles per year. This was stated by Andrey Matsarin, director of SPb GKU "Directorate for Road Traffic Organization of St. Petersburg".
The technology is called V2X. Essentially, it is wireless communication between transport and road infrastructure, allowing them to exchange information. One application of such a system is precisely the priority passage of trams through traffic lights.
Absolute priority works as follows: the carrier pre-sets acceleration at traffic lights in the schedule. Thanks to this, the tram achieves the necessary movement dynamics and can maintain a given average speed on the route.
As an example, Matsarin cited the Chizhik tram. When a tram leaves one traffic light and approaches the next, the system transmits a corresponding signal. The controller of the next traffic light pre-builds the cycle so that the tram can pass the intersection without a sharp change in movement mode and without creating problems for other directions.
Currently, absolute priority operates on nine GET routes. As a result, the travel time through traffic lights has been reduced by 8–9%.
On one of the routes, this was enough to reduce the number of trams from 31 to 30. And the total savings for Gorelektrotrans from the technology amount to about 40 million rubles per year. The implementation of this system began in 2023.