CARMEL, Ind. -- A major road closure in Hamilton County will force thousands of motorists to navigate detours for weeks to come.

Crews shut down a portion of Keystone Avenue in Carmel early Monday morning. The closure will be in effect for the next 45 days.

The road is closed from 126th Street to 136th Street. Motorists on 126th Street will have access to southbound Keystone, but northbound motorists will be forced to exit at 126th Street.

Both lanes are open between 136th Street and U.S. 31 during the closure.

Detour signs have been erected to guide motorists around the construction zone. Elsewhere in the construction zone, the speed limit is 30 mph in some areas and 40 mph in others.

Jeremy Kashman, manager of the Keystone project, said they opted to shut down the road instead of shifting and cutting lanes because the project will be done faster and less expensively.

"It will save $530,000, and the project will get done quicker," Kashman said.

The three-year project to lower the grade of Keystone under six intersections is nearing completion.

It has caused some travel headaches, but many think the end result of years of work will be worth it.

"It just makes all the quick trips very long," said Sherese Harbour, of Carmel.

"I guess it's progress," said Wayne Long, of Carmel. "Getting through here was difficult on Keystone anyhow. This is going to make it so much nicer."

Business owners are eager for the project to be over because it is cutting into profits.

"It makes it difficult for people to get around Carmel," said Holly Piercy, an employee at Butler Barbershop.

All traffic lights will be eliminated from 98th to 146h Street as part of the project. Roundabouts are being installed on some cross streets.

The entire project, which cost about $112 million, should be finished by mid-September.