Versions of s. 121(3)

If the Agency determines a rate under paragraph (2)(b), the companies that operate the route shall pay a shipper who moved traffic over the route an amount equal to the difference, if any, between the rate that was paid by the shipper and the rate determined by the Agency, applicable to all movements of traffic by the shipper over the route from the date on which the application was made to the date on which the determined rate comes into effect.