The real-time urban traffic control system CRONOS: Algorithm and experiments

Exposure to lateral collision in signalized intersections with protected left turn under different traffic control strategies

“…One-hour samples are large enough to ensure homogeneous and stable conditions and short enough to guarantee the independence of traffic volumes from traffic control strategies (Midenet et al, 2004;Boillot et al, 2006). If there is no red light violation, Z is inferior or equal to the sum of green and intergreen (yellow plus all red) periods.…”

“…The aim was to compare the CRONOS strategy with a time plan strategy with vehicle-actuated ranges, called here the baseline strategy (called the L-STRAT strategy in (Boillot et al, 2006)). Half-day recordings have been collected over several months during weekdays between 08:00 and 18:30, while one of the two control strategies was controlling the intersection.…”

“…Using estimated total crossing hourly volumes, we defined several classes of traffic conditions. Further details on this experiment can be found in (Midenet et al, 2004;Boillot et al, 2006).…”

“…This paper proposes an original measure of exposure to lateral collisions and evaluates the impact on this exposure of the real-time adaptive traffic control strategy CRONOS. This traffic control strategy -CRONOS stands for ContRol Of Networks by Optimization of Switchoverswas developed in the 1990s (Boillot et al, 2006) and relies on video sensors that provide queue lengths and spatial occupancy rates every second (Aubert et al, 1996). Its algorithm controls the traffic lights in order to minimize total delay over a shortrange time horizon.…”

“…The CRONOS strategy was compared to a standard time-plan based control strategy with vehicle-actuated ranges during a real world experiment. The comparisons between strategies in terms of fluidity criteria and environmental impacts have been published previously (Midenet et al, 2004;Boillot et al, 2006). The present paper deals with a safety comparison.…”