Study on Traffic Flow Characteristics in Mixed Automated and Manual Driving Conditions

The development of smart highways and automated driving technology, autonomous cars have been shuttling in the real world, and the most studied are Level 2 and Level 3 autonomous driving systems at present. But even in the L4 level automatic driving system, the driver still needs to take over vehicle control under limited conditions. In the future, autonomous cars and manual cars will long-term coexistence and the characteristics of traffic flow in this period will be very different from the traffic flow characteristics of current manual cars. In this paper, a numerical simulation environment of mixed traffic flows are constructed by using cellular automata (CA) model and the CAV car-following model, and studied the traffic flow characteristics under mixed conditions in combination with the actual expressway environment, and researched the influence of automatic cars on the running state of traffic flows under different proportional penetration conditions. The findings show that the ratio of automatic vehicles on the road increases, the greater maximum capacity of the road, the greater number of vehicles on the road before huge traffic jams has increased, the average speed of vehicles in unblocked roads and general traffic jams has raised to a small extent, and the average speed of vehicles in huge traffic jams has been significantly improved, accordingly with the reduction in travel time.