It likely will take several years before highway planners break the bottleneck on I-15 between North Salt Lake and Bountiful, a traffic engineer says.
Douglas Hattery, an engineer with the Wasatch Front Regional Council, said planning is under way to add a lane on both northbound and southbound I-15 and make other short-term improvements, mostly in south Davis County.But he said it will take at least three years to complete the planning process, conduct an environmental impact study and obtain state approval to spend an estimated $13 million to upgrade I-15 from 600 North in Salt Lake City to 200 North in Kaysville.
Hattery, who outlined the I-15 North Corridor study Wednesday for the Legislature's transportation interim committee, said planners also are beginning to consider an estimated $143 million in proj-ects to improve interstate traffic flows north from Salt Lake County over the next 20 years.
The keystone will be the long-awaited West Davis Highway, which will provide an alternative route running between the existing freeway and the Great Salt Lake.
Hattery said planners are talking with officials in communities that would be affected by the future highway to work out a proposed route, evaluate alignments and resolve other issues.
Planning funds for the short-term improvements have been provided through a recent $19 million bond issue approved by a special session of the Legislature in April.
Hattery told lawmakers it will take about $6.5 million to add the two extra lanes on I-15 from its junction with I-215 to the 500 South interchange in Bountiful.
It will cost another $6.5 million to upgrade or extend 14 on- and offramps, relocate frontage roads, install three new traffic signal systems and extend three northbound lanes through the Beck Street interchange.
In addition, the Utah Transit Authority will increase the frequency of its runs from Salt Lake City to Ogden and add new routes to Salt Lake from the Layton-Fruit Heights, Farmington-Centerville and West Bountiful areas.
Hattery said the study does not recommend establishing high-occupancy vehicle lanes to promote car-pooling because the lanes would not save enough time under current conditions to persuade commuters to form car pools.