A day after a series of closures to Interstate 5 caused massive traffic gridlock in the Phoenix area, the state has reopened its busiest highways and is working to alleviate the congestion caused by the road closures, a state transportation official said.

The state Department of Transportation, which manages highway operations in the Arizona area, said Wednesday that the highway closures are now over and the highway construction project is complete, with no more highway closures planned for the week of Dec. 23.

The agency said it will now start construction on the remainder of the highway system, which is the third phase of a $1.6 billion project to extend Interstate 5 from downtown Phoenix to downtown Tucson.

The agency said the new highway will allow more people to use the region’s busiest roadways for their daily commutes.

It is expected to open by the end of 2019.

“This is the first of its kind in the state of Arizona,” said state transportation commissioner Mike DeLong, who was joined by state transportation chief Jim Hightower in announcing the closure.

“We are very grateful to our citizens for their patience and for their hard work.”

While the new Interstate 5 will be able to operate during peak periods, it will be closed during the weekend.

DeLong said the project will likely be completed by the holidays.

The project will not impact the current Interstate 4, which will remain open.

The closures forced commuters to travel in groups of two or three, as well as people who were stuck in traffic.

Some drivers were stuck at traffic lights because the highways were closed.

DeLong said it’s likely that the work will cost $1 billion or more, though he did not specify what that number might be.

He said it would be an “overhaul” of the entire Interstate system.

“We will have a better idea of how that project will be funded,” he said.

“It will be a multi-year process.”

He also noted that the closure is not necessarily temporary, since the highway is only a short distance from a new interstate tunnel that will eventually connect Phoenix to Tucson.

He also said that the state will work to get more people using Interstate 5 by creating more traffic flow, including in the city of Tucson, which has a high concentration of commuters.

The construction project was approved in January 2016 by Arizona voters.

DeLafrance, who had been on the state’s transportation committee, said that while the interstate closure is a significant setback for commuters, it is a temporary setback, but that the overall project is not expected to affect the highway traffic.

The interstate was built in the 1960s to connect Phoenix with Tucson.

It was also the route taken by a number of major traffic routes before the interstate’s closure, including Interstate 80, Interstate 20 and Interstate 10.

The Arizona Department of Public Safety and Homeland Security, which oversees the highway, also said in a statement that the road construction project has been successful, though there are still several hurdles that need to be overcome.

The department said the construction will be completed and the state roads will be ready for the next phase of construction, which includes extending the highway from downtown Tucson to downtown Phoenix.