 On September 21, 2005, the State of Utah and the Sierra Club (acting on behalf of numerous groups opposing the overall Legacy Highway project) officially signed a compromise regarding Legacy Parkway.Some of the agreements reached include no billboards along the route, no semi-trailer trucks allowed on the parkway (except in cases where they are used in response to an accident or there is construction on I-15), and a speed limit.The speed limit on the parallel I-15 is ; however speeds in the leftmost lane can reach upwards of .