Every bridge has its capacity limits; there are many that may be driven over only by vehicles up to a certain permissible weight. Solutions are needed to identify these vehicles. Volkmann Strassen- und Verkehrstechnik, a major German company in the field of road and construction site safety, use Blickfeld’s Cube 1 3D lidar sensors in their solution for this issue. The device identifies ineligible (overweight) vehicles and safely diverts them before they cross and pose a risk of damage to the structure.
In practice, it would not be feasible to measure each vehicle individually off the track on a static scale, because the traffic flow would come to a standstill, or at least cause delays and congestion. Therefore, weight measurement must take place while the vehicle is in motion. However, this presents technical challenges in clearly assigning the weight to a vehicle, and in taking photos of the licence plates of ineligible vehicles, as required for evidence assessment by the authorities.
The unambiguous assignment of a weight to the correct vehicle is very important for data protection reasons, so photos are taken only of ineligible vehicles—and thus no photos are taken of vehicles that comply with the regulations. Volkmann have developed a measuring system to avoid taking improper photos, and that’s where the capabilities of the Blickfeld Cube 1 sensors come in. They record the entire test field three-dimensionally, so it can recognise how many of what types of vehicles—cars; trucks; cars with caravans; vans; motorcycles, etc—are in which position on the measurement track at any given time, and to which the respective measured weight can be assigned when an axle is crossed. Based on this combined information, weight plus assignment to a vehicle, an identification number is assigned to each vehicle. This ID is the prerequisite for the system to trigger the camera when a vehicle exceeds the permissible total weight. Since lidar sensors record the scene anonymously, the right to protection of drivers’ personal data is always upheld. Now the measurement system was recently tested very successfully on a private company site, Volkmann will be deploying it for the first time this year on a federal highway to protect bridges there from overloading. Taking the large number of weight-restricted bridges in Germany into consideration—2,700 are considered in need of refurbishment and are scheduled for modernisation by 2030—rapid expansion to other locations is likely.
Blickfeld are now demonstrating that lidar can also participate, with other sensing systems, in a precise characterisation of vehicles in terms of dimensions and weight in different areas where geofencing must be applied. Infrastructure equipment is another market for lidar technologies.