Connected and autonomous vehicles coordinating method at intersection utilizing preassigned slots

Connected and Autonomous Vehicle (CAV) technology contributes to the possibility of slot-based intersections (SIs). SIs allows vehicle to cross the intersection through the gap between two vehicles that are coming from the conflicting direction. A slots preassigning method is proposed in this paper. A status adjusting area is set up to realize the method. When vehicles enter the status adjusting area, manage center begins to calculate the target status that each vehicle should reach and generate vehicle operating suggestions based on method of Location Optimization On Sequence Evaluation (LOOSE) and Cooperative Optimization Method for Previous Allocation Alternatively Transforming (COMPACT). LOOSE is mainly used for keeping vehicles safe. And COMPACT is applied based on LOOSE, to generate vehicle operating suggestions and improve the traffic efficiency. As long as the vehicle follows the suggestions and maintains the optimal speed, the vehicle would cross the intersection without stop and collision. A simulation environment has established to evaluate the effectiveness of the approach. The results showed that capacity of preassigned SIs increases as defined minimum safe gap decreases. The capacity reaches its maximum in the condition that traffic flows from different directions are equivalent. And the proposed method performs better than signal based intersections.