Several studies, mainly simulation-based, suggest that, beyond any safety, convenience and environmental features, some VACS have indeed direct implications on traffic flow efficiency at varying levels. They also suggest that:

• The identified effects are not always positive
• Controversial conclusions sometimes emerge
• No unified study approach is available
• Effects are still neither fully analysed nor fully understood
• VACS contribution to the improvement of traffic efficiency may be enabled or enhanced by:
  • the use of traffic-adaptive settings
  • the extension of their communication and cooperation capabilities
  • the increase of the market penetration rate
  • the combination of different functions.

Last not least, since the simulation studies of VACS indicate that they can affect traffic flow both positively and negatively, they may lead to a deterioration of the overall traffic conditions, if left unsupervised to serve their individual users’ aims in a conservative, myopic and/or selfish for the collective traffic flow way. On the other hand, VACS may offer significant benefits, if deployed appropriately by traffic management, and if traffic management is allowed and prepared to “intervene” cooperatively at varying levels and different aspects of the driving task to influence the driving behaviour in favour of the global traffic conditions.

Last updated on 24/04/2015.