The traditional approach to determine access fee for a toll road is based on the type of vehicle, mostly on the number of its axles. In reality, the key damaging factors for the road infrastructure, particularly the pavements, are the vehicle gross weights and their individual axle loads. Thus, the traditional tolling only vaguely incorporates the true vehicle actions on the infrastructure.

In line with the 'polluter pays' principle, the fee for using a toll road should be proportional to the wear caused by the vehicle. At weight-based toll roads the road users pay according to the actual weight of their vehicles. The WIM systems not only ensure fair toll prices but may also generate additional revenue to finance maintenance of the infrastructure.

A WIM system can be integrated into both types of existing toll collection systems: with manual toll collection at toll plazas and as a part of electronic toll collection under free traffic flow. In both cases the toll fees can be collected with greater efficiency.

Finally, the WIM system can be used to detect overloaded vehicles.

Depending on the local conditions, the these may be denied access to the toll road to protect the infrastructure or may have to pay an extra fee to cover the costs for the additional damages.