(12)Toll systems based on automatic number plate recognition (ANPR) technology require more manual checks of toll transactions in the back office than systems using OBE. Systems using OBE are more efficient for large electronic toll domains, and systems using ANPR technology are more suitable for small domains, such as city tolls, where the use of OBE would generate disproportionate costs or administrative burdens. ANPR technology can be useful in particular when combined with other technologies.