CHICAGO — Illinois’ Department of Transportation is inviting public comment on its latest rail plan that includes station upgrades and improvements on the Chicago-St. Louis passenger corridor.

States are required to update their plans every five years. People can view Illinois’ proposed plan through the department’s website and submit comments. The deadline for commenting is Feb. 23.

A Tuesday IDOT statement cites Transportation Secretary Randy Blankenhorn as saying it’s critical for Illinois to continue improving its rail infrastructure “to maintain and strengthen” the state’s “status as the transportation hub of North America.”

Illinois has the second largest rail system in the country. And Chicago is widely considered the heart of the national system. Some 500 freight trains, along with 700 commuter and intercity trains, operate in the city daily.