The arrival of traffic flow at an intersection is often random and fluctuating. Therefore, the efficiency of signal control depends on how well the signal timing responds to the traffic flow that fluctuates every minute. Since actuated control can highly adapt to changes in traffic demand and traffic patterns, it can significantly reduce delays, while comprehensive detection information also enables the controller to effectively allocate time within each cycle.

A key feature of actuated control is that all phases are actuated: if no vehicles or pedestrians are detected, the phase can be skipped, and the signal controller will allocate the time to subsequent phases.

The case intersection is a "T"-shaped intersection. At this intersection, the volume of through traffic is relatively large, the proportion of U-turn vehicles is relatively high, while the traffic volume on surrounding lanes is small and unstable, and the traffic volume increases on weekends and holidays.

When fixed-time signal timing control is adopted, the mismatch between fluctuating traffic volume and the timing plan leads to obvious green light idling (i.e., green lights with no vehicles passing) and queuing at the intersection, resulting in a great waste of road resources. Additionally, the pedestrian flow is small and irregular, which increases the duration of the signal cycle and is not conducive to the reasonable allocation of green light time.

To improve the operational efficiency of the case intersection, reduce green light idling, and optimize the pedestrian green light duration, Marui Data has designed an actuated control algorithm based on the actual operation of the intersection. This algorithm can identify the traffic operation status according to the traffic flow occupancy situation and transmit the occupancy signal to the traffic signal controller. The controller then configures the corresponding green light release ratio based on the arrival of traffic flow in each direction, enabling efficient operation of the intersection.

In combination with non-contact pedestrian detection and warning devices, pedestrian actuated control is implemented. Through a comprehensive reminder system including sound, light, and LED displays, the safety of pedestrians crossing the street is enhanced, and the coordination between the actuated control for motor vehicles at the intersection is improved¡ªultimately boosting the overall operational efficiency of the intersection.

For the southbound direction, the integrated radar-vision-magnetic detector is installed on the crossarm of the opposite traffic light. Two rows of detection sections are set up in the southbound direction: the tactical detector is located 28 meters from the stop line, and the strategic detector is located 100 meters from the stop line.

For the westbound direction, the integrated radar-vision-magnetic detector is installed on the crossarm of the opposite traffic light. Two rows of detection sections are set up in the westbound direction: the tactical detector is located 20 meters from the stop line, and the strategic detector is located 100 meters from the stop line.

For the northbound direction, the integrated radar-vision-magnetic detector is installed on the crossarm of the opposite traffic light. Two rows of detection sections are set up in the northbound direction: the tactical detector is located 30 meters from the stop line, and the strategic detector is located 95 meters from the stop line.

At the case intersection, a hybrid actuated control system for motor vehicles and pedestrians is implemented. When a motor vehicle variable phase step has completed its minimum green light duration, if a traffic demand is detected for the current phase:

¡¤ If the motor vehicles can finish passing within the fixed-phase green light duration, the system proceeds to the next phase;

¡¤ If not, the green light duration is extended by a unit increment, with the maximum extension not exceeding the maximum green light duration.

When the pedestrian phase has completed its minimum green light duration:

¡¤ If a pedestrian crossing demand is detected, the pedestrian green light duration is increased by a unit increment, with the maximum increment not exceeding the maximum pedestrian green light duration;

¡¤ If no pedestrian demand is detected, the system switches to the next phase.

Currently, tactical detectors are used for vehicle status detection. The detection sections are distributed within the range of 20 to 30 meters, which is calculated based on the road speed limit and interval time to ensure vehicles pass through the stop line smoothly.

After the activation of actuated control, the green light duration can dynamically adjust in response to changes in traffic flow. This effectively reduces green light idling and secondary queuing caused by the uncertainty of traffic flow fluctuations, leading to a significant improvement in the traffic efficiency of the intersection.