Adaptive signal control technology adjusts the timing of the green, yellow, and red lights based on current traffic conditions, instead of relying on the pre-programmed signals of traditional intersections. When used along arterial highways and corridors, adaptive systems can improve traffic flow, reduce congestion, and make roadways more efficient. If you are looking to introduce an adaptive system into your area, you should select a corridor that will exemplify the benefits of an adaptive system. Keep in mind that not all corridors will benefit equally; your selection should be determined not by which corridor has the worst current traffic conditions, but by which corridor has the potential to demonstrate the most improvement from an adaptive system.
The following seven factors describe a corridor that would be a good candidate for showcasing the advantages of an adaptive traffic system:
Adaptive systems require reliable, accurate detection all along the corridor. If the current detection method does not provide the detection coverage required by your preferred adaptive method, you may want to update to the Wavetronix SmartSensor Matrix and SmartSensor Advance. Matrix provides true presence detection for all approaches at the intersections, and Advance continuously tracks each vehicle’s speed, range and estimated time-of-arrival at the stop bar. Together they provide the adaptive system with the accurate detection data needed to keep the corridor flowing as efficiently as possible.
Perhaps the most influential factor when determining where to use an adaptive system is the variability of the traffic flow. To see the most benefit, implement an adaptive system in an area with a lot of variation in traffic demands, including the following situations:
Because adaptive systems actively adjust the timing and turn on of traffic phases, it is essential for intersections to provide flexibility in their timing. Standard four-way intersections that are not overcrowded often provide the most flexibility, and are therefore good candidates for an adaptive system. Innovative intersection layouts that eliminate or relocate left turns often place restrictions on the timing of the phases, preventing an adaptive system from effectively improving the intersection.
Adaptive systems are focused on vehicular traffic flow, so you will want to look for an area where the traffic is mostly vehicles. High volumes of other modes of transit—pedestrians, bike traffic, and public transit—put constraints on the system, which can reduce the benefits of an adaptive system.
If there are major midblock disruptions throughout the corridor, such as on-street parking or a busy parking lot, it may not be the best candidate for an adaptive system. The difficulties here are twofold: first, a high level of disruptions can negate the benefits of an adaptive system; and second, depending on how your detection is situated, you may not detect all of the vehicles entering and exiting the mainline of traffic.
The best candidate for an adaptive system has evenly spaced intersections all along the corridor. When adjacent intersections are too close, their proximity acts as a constraint that limits the flexibility of the adaptive system; conversely, intersections that are spread far apart operate best independently and not as part of a system.
A good candidate for adaptive signal timing is a corridor with signal timing that has not been recently updated. Updating these corridors can drastically improve the efficiency of the intersection, truly highlighting the benefits of an adaptive system.