Analysis of Kinematic Parameters and Driver Behavior at Turbo Roundabouts: Fid-Bau Portal

Analysis of Kinematic Parameters and Driver Behavior at Turbo Roundabouts

Guerrieri, Marco / Mauro, Raffaele / Parla, Giuseppe / Tollazzi, Tomaz

This study focuses on both vehicle kinematic parameters (speed and acceleration) and behavior parameters (critical interval and follow-up time) of drivers at turbo-roundabouts. Empirical evaluations of such parameters can be helpful in calibrating traffic microsimulation models or assigning behavior parameters to closed-form capacity models in turbo-roundabouts (gap-acceptance capacity models) and are also related to evaluation of vehicles pollutant emissions. The research was based on traffic process observed in the first turbo-roundabout implemented in the city of Maribor in Slovenia. In 2016 a great number of traffic samples were taken with high-frame-rate video recordings [ $> 50$ frames per second (fps)]. All vehicle trajectories were obtained with the methods and algorithms typical of the digital imageprocessing technique (DIP) by filtering the discrete signal of vehicle trajectories $f (t)_{i}$ with wavelet analysis. The research results showed that vehicle speeds on entry lanes are rather moderate (below $25 km / h$ , 15 m prior to the Yield line), whereas accelerations usually have values inferior to $2 m / s^{2}$ on arm lanes and to $1.5 m / s^{2}$ on ring lanes. The critical intervals $t_{c}$ [distributed according to an Erlang probability distribution function (PDF)] and follow-up headways $t_{f}$ (distributed according to an inverse Gaussian PDF) have, on the other hand, values in ranges of $t_{c} = 4.03 - 5.48 s$ and $t_{f} = 2.52 - 2.71 s$ , respectively, according to the right- or left-turn lane and to the major or minor entry in question.