Micro-simulation effectiveness in predicting operating speed profiles in a roundabout

Roundabouts affect operating speeds depending on a number of parameters. Consequently, their performance affects urban transport systems (safety, environmental and operational impacts) and tools are needed to carry out operating speed predictions. To this end, note that roundabout traffic management and control can be carried out by using road traffic micro-simulation models when a calibration is provided. As a result, the objects of the paper are: i) to use micro-simulation and experimental investigations to analyse operating speed vs. geometry relationship in a roundabout; ii) to calibrate a micro-simulation model; iii) to assess micro-simulation effectiveness in predicting operating speed profiles approaching a roundabout. Driver speed profile was studied and a procedure to predict the operating speed-profile was developed. The data derived from traffic micro-simulation were compared with experimental data. The study permitted to derive several conclusions about operating speed-profiles, micro-simulation effectiveness. Furthermore, it permitted to assess the relevance of a number of parameters in terms of speed prediction and software calibration.