An interchange to solve traffic problems at one of the most congested sites in Davis County will cost up to $10 million and require the demolition of nine homes and a store, according to state traffic engineers.The proposal for an interchange at the intersection of U-193 and U.S. 89 in north Davis County is being made by the Utah Department of Transportation as one of the first steps in the eventual conversion of U.S. 89 to a limited-access expressway.
UDOT's study of the intersection, which handles much of the civilian worker traffic into and out of Hill Air Force Base, says construction of the diamond-shaped interchange will have little environmental impact.
The interchange design preferred by UDOT engineers includes an overpass over U.S. 89 and four on- and off-ramps, in addition to two service roads and a stoplight.
It is designed to move traffic onto and off U-193 - also known as Hill Field Road - from U.S. 89 without affecting the traffic flow on the main highway.
Construction of the service roads on the east and west sides of U.S. 89 will require the removal of nine homes and a dairy store, according to the plan.
But UDOT pre-construction engineer Lynn Zollinger said a second construction design using a three-tiered interchange drawn up by design engineers would have required removal of two more homes and cost an additional $3 million.
The favored design also has no impact on three residential sites in the area that are considered to have historical importance, according to UDOT.
Zollinger said the environmental impact study shows that construction of the interchange will have some minor impact on wetlands, air quality, noise pollution and water quality. But those impacts can be mitigated so that they are acceptable, UDOT believes.
Zollinger said UDOT wants to put the project out to bid in the fall of this year and begin construction in early 1992.
The environmental impact study also took wildlife into consideration. The proposal includes fencing along U.S. 89 to keep deer from crossing the highway.
"Approximately 16 percent of all the accidents in this area are related to wildlife crossing the highway," the study determined. "The proposed action would include fence to prevent deer from crossing the highway.
"Warning signs would also be posted to alert the public to the hazard."
Among local residents, U.S. 89 is called the Mountain Road because it skirts the foothills of the Wasatch Mountains immediately to the east. In many places, thickly wooded hills rise steeply directly off the highway shoulder and support large deer herds.
Just north of the proposed interchange, U.S. 89 drops steeply into the Uintah dugway at the mouth of Weber Canyon. Residents who live in that section warned UDOT engineers at previous public hearings about instances where herds of deer, wandering onto the highway at night, have been trapped between the high banks on both sides and slaughtered by heavy traffic.
UDOT engineers, supported by officials of cities adjacent to U.S. 89 through Davis County, are studying the eventual conversion of the highway into an expressway to serve as a second transportation corridor between Ogden and Salt Lake.
An initial study by a transportation consulting firm two years ago estimated the cost of conversion, including interchanges, overpasses and frontage roads, at $80 million. That figure does not include the cost of buying land to build the frontage road and on- and off-ramp systems.
A public hearing on the proposed U.S. 89 interchange is set for 7:30 p.m. Thursday, Feb. 28, in the Layton High School Auditorium.