The Illinois Department of Transportation and Union Pacific Railroad are performing another phase of upgrades to Illinois’ signature high-speed route, Chicago-St. Louis, for future 110 mph operation of Amtrak Lincoln Service trains.

The construction work includes the installation of new premium rail with concrete ties and stone ballast; upgrades to bridges, culverts and drainage; signal and wayside equipment installations and upgrades; and roadway-rail grade crossing improvements.

For eight days starting August 16, bridge and culvert upgrades north of Bloomington-Normal will lead Amtrak to charter buses for Lincoln Service (Trains 300-307) passengers at St. Louis, Alton, Carlinville, Springfield, Lincoln, Normal, Pontiac, Dwight, Joliet and Summit, Ill.

Amtrak Texas Eagle (Trains 21/321/421 & 22/322/422) will detour between Chicago and St. Louis for the same period, with alternate transportation in both directions between Joliet and St. Louis. Two more phases of planned 2013 construction will also require substitute transportation.

To expedite travel between Chicago and downstate, many of the buses will connect to and from Amtrak Illini and Saluki trains in Champaign-Urbana to avoid Chicago suburban highway congestion and downtown Chicago traffic.

These infrastructure improvements will allow Union Pacific crews to enable Amtrak to operate service at speeds up to 110 mph, an increase from the current maximum of 79 mph in effect over most of the route. Starting last Thanksgiving, the Dwight to Pontiac segment became the first part of the corridor to regularly experience trains traveling at speeds up to 110mph.

In the nine months since October 2012 (Amtrak Fiscal Year 2013), ridership on the Chicago-St. Louis corridor has increased by nearly 23,000 when compared with the same period a year ago, totaling more than 551,000 passengers — an increase of 4% that sets the stage for another record breaking year, according to Amtrak.