The Utah Department of Transportation will optimize mobility for drivers from the Brigham City and the Cache Valley (U.S. 91) areas by converting the existing 1100 South interchange at Interstate 15 to a Diverging Diamond Interchange (DDI). The new interchange will be essential to accommodate the tremendous growth in the Brigham City area over the past decade.
The 1100 South DDI is northern Utah’s first. A DDI is a relatively new interchange concept in which both directions of traffic are crossed to the opposite side to provide easier access on and off the freeway. This reduces the number of traffic signal phases needed to move motorists through the interchange to two, as opposed to the usual three or four.
DDIs efficiently move high volumes of traffic without increasing the number of lanes in an interchange. Since 2010, UDOT has constructed successful DDIs at four locations: I-15 in American Fork at Main Street and 500 East, I-15 in Lehi at Timpanogos Highway and Bangerter Highway in Salt Lake at 2100 South.
Interchange renovations include:
<ul> <li>Constructed Diverging Diamond Interchange</li> <li>Reconstructed roadway including removal of the old road as well as some base materials</li> <li>New drainage system</li> <li>New signage and striping</li> <li>Widened interchange lanes including the shoulders and auxiliary lanes</li> </ul>
In 2013 the Utah Legislature allocated $12 million for Brigham City interchange improvements. While it has been a priority, the amount is far less than the cost of a typical interchange. Instead of building the interchange from the ground up, UDOT will use as much of the existing interchange as possible, and the state will not need to purchase any property for the project. This allows the existing interchange to remain in operation and provides significant cost savings to taxpayers.