The Arizona Department of Transportation is replacing the bridge at Chinle Wash on the Navajo Nation in far northeastern Arizona.
The $6 million project is scheduled to start Monday and be completed by the end of this year.
The new three-span bridge will be 280 feet long and nearly 9 feet wider than the current bridge on U.S. 160.
ADOT officials say the project also will realign the roadway and install new pavement markings, among other improvements.
They say motorists using U.S. 160 through the area while the bridge is being replaced should expect delays up to 20 minutes just west of Mexican Water on the Navajo Nation.
A temporary traffic signal will have traffic alternating through one lane on the existing bridge.