Priority traffic light regulation for public transport

Summary

The high density of vehicles in Craiova has led to an increase in traffic and leads to stress for drivers, pedestrians and passengers. The city has made an effort to pay more attention to prioritising public transport in traffic. Therefore, a system called green light to save time for trams will be introduced.

Implementing sustainable mobility

A traffic light priority system will be introduced to all public transport vehicles to circulate more fluidly.  To achieve this, nine tramways will be upgaded within the energy saving on tramline measure. The trams will be equipped with a chopper as part of that measure and onboard units that ensure they are prioritised at traffic lights as part of this one. Timing traffic lights have already been introduced and the traffic lights at many intersections were replaced with roundabouts in order to reduce waiting times at traffic lights during peak hours. As part of this measure three traffic light plants will be upgraded with specific priority hardware and software. The tasks planned for the implementation of the measure are clustered on research and development activities, DEMO applications, training, evaluation and dissemination activities.

Progress

As part of the research and technical development stage, an analysis of the existing situation and the possibility to implement a priority system for public transportation in Craiova was carried out. The municipality has already initiated a project for the construction of roundabouts in the city's main intersections in order to streamline the traffic. The specific application was studied and a technical solution defined. The electronic control device for priority is included in the onboard computers of 9 trams. 

The green wave for trams involved in this measure gives the responsibility of traffic light command to the watt man. The radio module (emitter) is connected to the tram board computer and has a processor that transmits a batch of 10 to 50 data packages containing information related to the ID number of the vehicle, timestamp, package identification number and a cyclic redundancy checksum. To avoid any possible false commands on different directions a different frequency is used for each direction. Training will be given to technicians using the data and special devices and to drivers operating the system.

Outcomes

Craiova expects that the measure will:

• Improve the traffic flow;
• Avoid crowding in the city main intersections; and
• Create a system for granting preferential priority for trams to reduce travel time.