A shadow toll is a contractual payment made by a government per driver using a road to a private company that operates a road built or maintained using private finance initiative funding. Payments are based, at least in part, on the number of vehicles using a section of road, often over a 20- to 30-year period. The shadow tolls or per vehicle fees are paid directly to the company without intervention or direct payment from the users.
On more recent shadow toll schemes in the United Kingdom, payments reduce as the number of vehicles increases, to encourage availability of the road rather than the number of vehicles carried.