4.17 - Speed Management in Single Carriageway Roads: Speed Limit Setting through Expert-Based System

Project Description

Despite the widespread use and acceptance of speed limits throughout the world, no consensus was so far achieved among practitioners on the methods and techniques to be used to select the appropriate speed limit in a given road section. Besides, the ever growing urban development in most roads surrounding areas has in many countries led to the existence of not only purely rural environments, but also disperse and non-consolidated built-up areas in their surroundings. The boundaries between these zones are very often difficult to clearly identify, which has resulted in an ever more frequent occurrence of complex road environments. A number of approaches has been developed and adopted in different countries to set speed limits in interurban roads. Most of these methodologies usually give prevalence to the geometric features of the road layout. However, given the complexity of the road environment, a wider set of factors related to the surrounding areas, safety, traffic and users must be included.
Hence, the major objective of this thesis is to provide a generalized decision-support methodology for speed limit setting in interurban single carriageway roads, crossing different types of road environments with a mixed or urban use, considering a range of significant and objective variables. Moreover, this thesis aims to deliver an accessible and easy to use methodology by the technical community, whose required data must be collected based mostly on remote sources and easily measurable information. Therefore, it will be considered an expert-based approach emphasizing factors related with the prevailing road environment, especially focusing on road integration into the surrounding areas. The development of this process must focus on three different levels of the road, from a more detailed to a more general view: (I) Analysis at the road section level; (II) Analysis at the road stretch level, involving a number of adjacent sections, and particularly focusing on transitions from section to section; (III) Analysis at the route level, involving a longer sector of the road comprising a significant number of contiguous stretches, and focusing on issues related with safety, economic and environmental effects. The final outcome of this thesis shall integrate all these three components, in the most coherent and objective way possible.

Research Team
  • Nuno Gregório
  • Álvaro Seco (supervisor)
  • Ana Bastos Silva (supervisor)
Financial Support
  • PhD Scholarship granted by FCT, under the MIT-Portugal Program
Stage of Progress
  • In Progress