Inductive Vehicle Detection Loops

Have you ever seen a section of a road that seems to have lines cut straight into the asphalt, these lines forming a beveled rectangle or a circle? Or perhaps you’ve driven up to the parking lot gate and found a foreign object sitting directly in your path with a wire leading off to the side. These are a few examples of a vehicle detection system called an induction loop. Induction loops are wires that create a loop inside which a magnetic field resonates. These loops are powered by a detector box, which also connects to a device that reacts to the magnetic field’s changes, such as a traffic light, gate, or vehicle counter. When a large metal object–like a vehicle–moves over the loop, the magnetic field is strengthened and sends a signal to the detector, which triggers the other connected device to act accordingly. When a vehicle passes or arrives at a point marked with an induction loop, this strengthens the magnetic field and signals a response to the other device connected to the detector, creating a hands-free, automatic operation process.

At VehicleLoops.com, we offer three different types of vehicle detection loops. What kind you decide to go with depends entirely on the state of wherever you are planning to place it, as well as any laws or safety hazards that may prevent you from cutting into the ground. If the vehicle-safe surface (concrete, gravel, asphalt) is not yet installed, or if there are plans to dig up what is already there and replace it, then a direct burial preformed loop would be the correct choice. The loop which creates the magnetic field for detection is encased in a water-tight conduit that protects it from damaging elements, such as sharp stones, heaving, chemicals, and inclement weather. These conduits can be pre-placed underground and encased in the material installed in the hole, making their inclusion clean and seamless.

If there are no plans to reinstall the ground material and an above-ground solution is impractical due to the typical speeds of vehicles that will pass over it, then a perfect compromise would be the introduction of a saw cut preformed loop. These are installed by cutting straight into the ground using a concrete saw and tucking the wire into the newly cut slots, protecting it with a sealant that will secure and protect it from dislodging or getting damaged. It may not be the prettiest solution, but what it lacks in visual appeal, it makes up for in accuracy, as it is easier to control the depth of the slots cut to fit the wires. The typical depth of these slots tends to be about 1”, making the wire and the resulting magnetic field closer to the surface and, therefore, closer to passing vehicles, allowing detection to be as accurate as possible.

Finally, your best option would be a surface-mounted loop in areas that are too small to use power tools safely within or in locations that prohibit the damage of any part of the property. These detection loops sit above ground and are encased in a protective dome, making the installation process even more straightforward than a direct burial or saw-cut installation. With each kit comes an optional adhesive and lead protection you can use during installation to secure your induction loop to its proper position. These are handy if you expect any interference to be shared, such as car tires nudging it out of place. This option is commonly used in post-tensioned concrete structures such as parking garages. It is considered an easy solution to the issue of being unable to cut into the ground.

Now that you know what these different products entail, which one is right for you? Whether you want to detect the presence of vehicles to activate a gate or light or if you need to keep track of the cars entering and exiting your property, we have you covered. Explore our extensive collection of differently sized vehicle detection loops to discover the most appropriate for your needs. Know that all our induction loops come fully assembled and ready to install so that you can start immediately!