There is a Portuguese project, called AROUND, which models “virtual roundabouts” to design real, safe and environmentally friendly roundabouts.
Roundabouts continue to be a good solution for managing the road network, as they are cheap and efficient compared to building a priority crossing or even installing traffic lights.
However, as a general rule, the design of roundabouts in Portugal continues to be carried out without any verification of the levels of capacity or safety, sometimes resulting in solutions that are inadequate to local needs.
From now on, similarly to what happens in other foreign countries, tools will be available in Portugal that not only support interventions in the current roundabouts, but also design new, safer and more environmentally friendly solutions.
A team of researchers from the Universities of Coimbra and Aveiro and the Polytechnic Institute of Viseu used virtual models to simulate the operation of different types of national roundabouts, adapting them to represent the characteristics of the Portuguese network and drivers.
These simulation models allow to represent the real road environment, from a simple intersection to a complex network that can cover an area or city, making it possible to test the operation of different road solutions before they are implemented.
In practice, these are microscopic models incorporated in software and which reliably represent the behavior of vehicles and their drivers (behavioral variability, speeds, acceleration rate, reaction times, etc.).
The team adapted the Spanish model Aimsun (one of the world reference models) to the reality of the national road network within the scope of the AROUND project (New Instruments for Operational and Environmental Assessment of Roundabouts), financed by the Foundation for Science and Technology (FCT) .
With the simulation down to the smallest detail, «based on these calibrated virtual models, it is possible to assess the impact on the network associated with different traffic demand scenarios, geometric changes, or new regulation solutions, etc., without being necessary the real intervention, often expensive. The model provides temporal profiles of position, speed and acceleration for each simulated vehicle, allowing the assessment of the global performance of roundabouts from an integrated perspective of fluidity, potential generation of accidents and environmental emissions», explains Ana Bastos, coordinator of the work and researcher of the Faculty of Science and Technology of the University of Coimbra (FCTUC).
The IT solution proposed by researchers from Coimbra, Aveiro and Viseu goes even further: «it also allows us to assess how innovative solutions work, such as turbo-roundabouts, even before they were built in Portugal, thus constituting as a decision support tool. Will a roundabout that now makes perfect sense in a given location will continue to be the most suitable solution a decade from now? – By answering these types of questions, it is possible to design roundabouts in an increasingly adequate way», exemplifies the specialist in Urbanism at the University of Coimbra.
The AROUND project included a pilot study for the implementation of the first turbo-roundabout in Portugal, which was validated in Grado, Asturias.
Author: Cristina Pinto (Press Office – University of Coimbra)
Science in the Regional Press – Ciência Viva
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