Automobile traffic grew quickly when the race track opened. The image below is typical weekend / holiday traffic on Northwest Highway, Route 14, at the intersection with Arlington Heights Road. Don't let the Route 12 sign throw you off. Route 12 ran along with Route 14 at that time.
When the traffic light turned red young children would jump into the street and state yelling at the top off the lungs;
"Racing Forums, Scratch Sheets, Times, News, American." That went on all morning long. (photo courtesy of Michael O'Connell)