Signalprioritet

Signalprioritet is the practice of adjusting traffic signal operations to grant priority to specific road users, most commonly public transit vehicles such as buses and trams, but also emergency services or, in some cases, bicycles and pedestrians. The aim is to improve reliability and travel times for prioritized modes while maintaining overall safety and efficiency at intersections.

There are several approaches to signalprioritet. Transit signal priority (TSP) uses detectors or central control to modify signal timing when a transit vehicle is approaching or queued. Techniques include extending green time, shortening red time, or inserting a phase to better accommodate the vehicle, potentially at the expense of cross traffic. Emergency vehicle preemption is a more immediate form of signalprioritet, where traffic signals briefly override normal sequencing to allow responders to pass quickly, followed by a rapid return to normal operation. Some systems also provide limited priority for pedestrians or cyclists, typically through longer green windows at corridors with high nonmotorized demand.

Implementation considerations include safety, reliability, and equity, as well as the potential for delays to other users if priority is overused or poorly coordinated. Effective signalprioritet requires detection technology (inductive loops, cameras, GPS, or vehicle-to-infrastructure), robust algorithms, and appropriate governance to balance competing needs. Benefits often cited are improved punctuality and service reliability for prioritized modes and potential reductions in emissions through more efficient operations, though effects vary by corridor and traffic conditions.

Across regions, signalprioritet is used in many metropolitan transit networks and in certain emergency response systems, with Scandinavia, Europe, and North America reporting active deployments in varying forms.