7.1. A carrier who has a contract with a railway firm shall be exempted from holding a permit for the interurban transport services that he provides to the clients of that firm under that contract, where the following conditions are met:
(1) the railway transport service must be suspended for more than 7 consecutive days to clear the tracks owing to an accident, or to allow construction work, repairs or maintenance;
(2) the carrier already holds a permit for an interurban transport service between the municipalities or urban areas located at each end of the route determined in the contract;
(3) the service provided under the contract is furnished according to the tariff for chartered transport filed by the carrier under section 45, or failing that, according to the tariff contracted with the parties.