Eight bus bays in downtown Salt Lake will be under construction through Oct. 21.

Acting on a request by the Salt Lake City Council, Utah Transit Authority is replacing the asphalt bus bays between South Temple and Fourth South on Main Street with concrete bays. Asphalt has a tendency to shift and creates safety hazards, while concrete is more durable, said UTA spokesman Craig Rasmussen.The construction will continue through Oct. 21. Alternate bus zones will be out of service during each construction phase. Construction is being staggered to minimize traffic congestion, Rasmussen said.

Changes in bus routes will be posted near the bus bays.

The project will cost $150,000. The city is paying for 20 percent of the project. UTA, through a federal grant, is paying for the remaining 80 percent.