Chicago runs on a street grid measured out from State and Madison in the Loop, with big arterials like Western, Ashland, Halsted and Cicero every mile or half mile. The expressways fan out from downtown like spokes. The Kennedy heads northwest toward O'Hare, where I-190 makes the final run to the terminals, and the Edens splits off toward the North Shore. The Eisenhower runs straight west to the suburbs, the Stevenson angles southwest past Midway, and the Dan Ryan carries the South Side toward I-57 and Indiana.
Those spokes are where breakdowns hurt most. The Kennedy's reversible lanes, the Circle Interchange and the Dan Ryan at rush hour leave a stalled car with nowhere to go, and Lake Shore Drive has narrow shoulders along much of the lakefront. Neighborhood streets are a different story. Most residential blocks have an alley behind them, and a car in a garage or on a parking pad off the alley is often the easiest place in the city for a mechanic to work. Winter adds snow-route parking restrictions on major streets, so check the signs before leaving a dead car on an arterial.
O'Hare and Midway are both regular service locations, since cars left in their economy lots come back to dead batteries after a cold week. The CTA L lines and Metra commuter rail cover most of the city and suburbs, which makes it easy to get to work while your car is repaired at home.