Washington State Department of Transportation (WSDOT), US, has started testing an all-electronic SR 520 toll system.

The system will be trialled over the next six weeks until mid-June to confirm its ability to process thousands of daily transactions and track revenues worth $1bn, which will help fund the State Route 520 Bridge Replacement project.

Initial testing will check that the photo-toll transaction processes properly and generates a bill with the correct toll amount, after which WSDOT will carry out full operational testing that starts with a photo-toll transaction on the SR 520 bridge.

Once the operational testing is complete, the department will set a start date for SR 520 tolling system, which must be ready to process and generate bills for the 20,000 photo-toll transactions that take place every day.

The photo tolling system will detect drivers with prepaid Good To Go accounts travelling on motorways, and will automatically deduct the toll amount from their accounts.