Urban arterial roads face an increasing number of serious problems. They are often not purpose built and thus have variable capacity. This leads to congestion which often has an adverse affects on buses and encourages rat running through sensitive areas adjacent to the arterial. They also usually have high accident rates. Project Primavera is concerned with using integrated ATT methods to try and solve these problems.Objectives
The main objectives of the project are to develop, test and produce recommendations for the application of integrated traffic control and management measures for urban arterial roads incorporating: queue control, public transport priority and environmental protection.Technical Approach
The project began by reviewing and developing techniques in the three areas of queue management, public transport priority and traffic calming. Each of the developed techniques has been tested individually by simulation of corridors in Turin and Leeds. The results have been used to aid the design of integrated strategies encompassing all three areas. These integrated strategies have also been tested by simulation to discover which combinations produce synergy. It is planned to implement the best strategy for each site during field trials.
It is expected that the field trials will demonstrate the possibility of achieving positive control of traffic on congested urban arterials in such a way that public transport is freed from the delays suffered by other traffic, rat-running through adjacent side streets is discouraged, levels of pollution are reduced, pedestrian safety enhanced, and the extent of traffic queues controlled.Achievements
Reviews of the state-of-the-art in the three areas of traffic control as applied to urban arterial corridors have been produced. Over forty individual strategies have been identified for further consideration. A Delphi style approach has been used to carry out an initial ranking of the strategies. Following this approximate ranking, simulations have been carried out on the best strategies in order to determine their effects more accurately. Integrated strategies have been developed which simulations indicate will produce significant benefits above those obtained by their component parts.
Computer software has been produced to allow the Italian micro-simulation model NEMIS to be linked to the UK SCOOT hardware, letting it directly drive the model. The NEMIS model has been enhanced to allow it to estimate the effects of each strategy on vehicle pollution emissions and fuel consumption.
Extensive surveys have been carried out at the field trial sites in both Leeds and Turin, to both calibrate the micro-simulation model and to provide 'before' data for the field trials. An evaluation methodology has been developed allowing consistent assessment of both the simulations and field trials.
The SCOOT and SPOT systems have been significantly improved to let them implement the chosen strategies.
A new inexpensive method of implementing selective vehicle detection is being tested in Leeds which will provide a practical way of giving priority to public transport.Contribution to Standardisation
The project is playing a leading role in the standarisation of the evaluation plans for the DRIVE 2 projects and it is hoped that the evaluation of the field trials will lead to design recommendations, for use by traffic engineers and planners throughout Europe, for ATT solutions of the problems facing urban arterial roads.Contact Point