Transient flushing is also a common side effect of alcohol, particularly in heavy drinkers. It is due to acetaldehyde, the main breakdown product of alcohol. Acetaldehyde is thought to cause flushing by stimulating release of histamine.
The right two lanes of the Tri-State Tollway become exit only for the ramp connection to Interstate 94/Bishop Ford (Calumet) Expressway west (north) to Chicago and Illinois 394/Bishop Ford (Calumet) Expressway south to Crete and Danville. An END Interstate 294 sign is posted on this guide sign.
Route 66 continues along IL 4 north through Virden, Thayer, to Auburn. A section of IL 4 north of Auburn and south of Springfield, which was also part of the original span of US 66, was listed on the National Register of Historic Places on August 6, 1998. This is the last brick alignment in Illinois. Route 66 then passed through Chatham, and entered Springfield.