The improvements for 110 mph service include the installation of new premium rail with concrete ties and ballast; upgrades to bridges, culverts and drainage; signal and wayside equipment installations and upgrades and grade-crossing improvements.

As of June 16, work will progress to north of Bloomington-Normal.

Union Pacific's track renewal train crews will improve infrastructure to enable Amtrak service to travel at speeds up to 110 mph, an increase from the current maximum of 79 mph. Illinois DOT and Amtrak are planning to preview higher-speed trains in September 2012 between Dwight and Pontiac. The Dwight to Pontiac segment will be the first part of the corridor to experience trains traveling at the higher speed.

This is the last scheduled year of large-scale construction leading to alternate transportation on the corridor. When work began with a ground-breaking north of Alton, Ill., in 2010, it was among the first high-speed rail projects in the country to begin construction.