With the co-existence of private vehicles and public transport in the urban context, there are sometimes conflicting interests for mobility managers. The promotion of public transport is still an unavoidable political objective in order to improve sustainability of urban environments.
Likewise, in suburban areas, promoting public transport to carry people to activity centers (industrial estates and shopping and financial centers), is conditioned by traffic jams at peak hours which are inevitably repeated on the major access axes. The success of collective transport largely depends on its capacity to avoid traffic jams, either by not travelling on roads (obviously the case of trains or tramways), or the availability of lanes reserved for this kind of transport resulting in higher average speeds.
Experience to date has shown the high effectiveness of adequate use of centralized traffic-light management systems to give priority to public transport, which helps to improve urban mobility´s management efficiency and networks sustainability.
• forced priority is adapted to situations where the beneficiaries have right of way because of their specific characteristics or functions. Hence, this is particularly applicable to the case of tramways whose dynamic capacities and lateral movements are limited or even non-existent, with the highway infrastructure having been adapted to their specific requirements. Also included in this category are shuttle buses which are common in USA and Canada and Latin American countries.
• prioritization of emergency, through provisional establishment of corridors, specifically adapted to the travel of emergency vehicles on the main city highways, permits strategies to be established that clear the highway to allow these vehicles to reach their destinations in short times and with the minimum number of obstacles taking into account their size (especially true for fire-fighting vehicles).
• selective prioritization, by means of specific action during phase changes, permitting interaction between support systems to the exploitation of bus and traffic light management networks, thus providing additional regulation capacity in order to increase and maintain a high quality of the service both in terms of commercial speed and particularly in terms of punctuality in urban trips.
Collaboration between public transport and traffic-light management therefore offers a wide range of possibilities to promote the use of public transport, minimizing negative consequences on private vehicles as much as possible.