Above Ground Detection v Traditional Inductive Loops

The difference between above ground vehicle detection and traditional induction loop detection

Vehicle detection is an essential component of traffic management systems, as it provides information on the presence, speed and direction of vehicles on the road. There are different methods of vehicle detection, but the most common ones are above ground detection and traditional induction loop detection.

Above ground detection uses sensors that are mounted on poles, gantries or other structures above the road surface. These sensors can use various technologies, such as microwave, infrared, optical or vision-based systems, to detect vehicles passing by or stopping in a defined area. Above ground detection has some advantages over induction loop detection, such as:

- Easy installation and maintenance, as there is no need to cut the road surface or disrupt traffic flow.

- Flexibility and adaptability, as the sensors can be repositioned or adjusted to suit different traffic scenarios or applications.

- Accuracy and reliability, as the sensors can detect all types of vehicles, including motorcycles and bicycles, and are less affected by environmental factors such as weather or road conditions  .

Traditional induction loop detection uses wires that are embedded in the road surface and connected to a detector unit. The wires form a loop that generates a magnetic field when an electric current passes through it. When a vehicle enters the loop area, it changes the magnetic field and triggers the detector unit. Induction loop detection has some advantages over above ground detection, such as:

- Low cost and long lifespan, as the wires are relatively cheap and durable once installed.

- Compatibility and standardisation, as the induction loop system is widely used and accepted by traffic authorities and manufacturers.

- Privacy and security, as the induction loop system does not capture any images or personal data of the vehicles or drivers.

Both above ground detection and traditional induction loop detection have their pros and cons, and the choice of the best method depends on various factors such as the traffic volume, speed, lane configuration, site layout, budget and purpose of the detection system. A hybrid approach that combines both methods may also be possible in some cases to achieve optimal performance and efficiency.