MICHIGAN — The state Department of Transportation has put Montana’s transportation safety net in jeopardy by imposing a travel ban on its borders, officials announced Monday.

The state Department has put travel restrictions on parts of the Northwest and Southwest, which means Montana has the second-highest number of people who have to fly back and forth to destinations.

The department said in a statement that Montana Transportation Secretary John P. Hinkle will issue a letter to all of the state’s agencies, and state agencies must comply.

The letter is designed to provide reassurance that the state can continue to operate safely as Montana moves forward with an ambitious plan to rebuild and upgrade its transportation infrastructure.

The Montana Travel Advisory Commission issued a travel advisory Monday.

It warned that travel restrictions could hamper the state from preparing to re-open as soon as January, when federal funding is set to expire.

Travel restrictions are typically imposed for emergency situations, but there are cases when a temporary restriction has been extended for an extended period of time, officials said.

The Montana Travel Association warned that the letter of warning could hamunleap Montana’s ability to meet the federal deadline to finish building a new bridge over the Mississippi River.

“Montana is a state of emergency and the safety of Montana citizens must be paramount,” Hinkle said in the statement.

“We are sending this letter to make sure that Montana can continue safely and securely operating, and that the public will continue to have confidence that Montana is in a position to complete this project.”