Here are some of the hurdles the Utah Department of Transportation must clear in preparing to build the West Davis Highway:

- Wetlands. Before issuing a federal permit to construct the roadway, the U.S. Army Corps of Engineers must be convinced the road is necessary and that the alignment chosen represents the least possible impact to the aquatic ecosystem. UDOT may have to put portions of the highway on bridges to satisfy this requirement. Because it chose an alignment already considered problematic by the corps, this is by far the largest obstacle the department faces.

- Railroad. Union Pacific wants UDOT to preserve an old railroad corridor it owns. That means building road structures above the rail line. The Wasatch Front Regional Council, meanwhile, has asked the transportation commission to purchase that right-of-way as a future transit corridor.

- Landfill. The preferred route would take out a portion of a landfill used by the city of Bountiful and alter the access, making it more difficult for residents to reach the dump. The city strongly opposes those plans.

- Timing. UDOT intends to build two U.S. 89 interchanges, at Cherry Hills and Shepherd Lane, before it constructs the three-way interchange of U.S. 89, I-15 and the West Davis Highway. Local officials want all three done at the same time to minimize inconvenience to motorists, residents and businesses.

- Farmington ramp. City officials want a connection from Burke Lane to the West Davis Highway in western Farmington.

- Transit funding. In order for the West Davis Highway and a rebuilt I-15 to handle the traffic volume expected in 2020, public transit must be improved, possibly including the introduction of a commuter rail service. Funding for such improvements, however, has not been identified.