Near the Cass Avenue instersection, Route 66 and I-55 pass by the northern edge of the Argonne National Laboratory campus. A mile or so further east near the IL 83 interchange, Dell Rhea's Chicken Basket in Willowbrook is still a popular stop for motorists on the route, although being cut off from the Interstate did cost it a significant amount of business after I-55 was built and during the 1960s through 1980s. At the Indian Head Park interchange with I-294 (Tri-State Tollway), I-55 separates from US 66 to follow a more southerly route as the Stevenson Expressway while Historic US 66 continues eastward on Joliet Road, passing by the historic Lyonsville Congregational Church at Wolf Road and traversing Countryside, Hodgkins and McCook.