Track work on the rail corridor used by Amtrak between St. Louis and Springfield, Ill., will mean closures on the line off and on for the next two and a half months, Amtrak announced.

On days when work is scheduled, Amtrak will bus passengers taking the Lincoln Service train between St. Louis, Alton and Carlinville and Springfield on motorcoaches and vans.

That alternative transportation arranged by Amtrak will leave an hour early to get to Springfield so the Lincoln Service trains heading north from Springfield can leave on time.

Texas Eagle trains between Chicago and San Antonio will be detoured around the work and won't have other scheduled stops in Illinois, Amtrak said.

The planned track closures are today through Sept. 8, Sept. 16-24, Oct. 1-9 and 16-23, and Nov. 1-9.

The track improvements, funded through federal stimulus money, will support future high-speed rail service on the line.

Union Pacific will install 220,000 concrete ties and 12 track switches between Springfield and Alton in the first phase of the project.

The Federal Railroad Administration grant of $1.1 billion for the entire St. Louis-Chicago corridor will allow trains to operate at up to 110 mph and includes new trains, passenger cars, track work, warning devices at crossings and safety technology, Amtrak said.