South Bend sits on the St. Joseph River just south of the Michigan line, and its roads follow the river's bend through town. The Indiana Toll Road runs along the north edge of the city, connecting South Bend with Chicago to the west and Toledo to the east. US 20 and US 31 form the St. Joseph Valley Parkway, known locally as the Bypass, along the south and west sides. US 31 also runs north toward Niles and Michigan, and SR 933 follows Michigan Street and Lincoln Way through town.
Inside the city, Ironwood Drive, Main Street, Michigan Street and Edison Road carry much of the traffic, and Grape Road in Mishawaka is the main shopping corridor for the whole area. Grape Road and the Bypass back up at rush hour and on weekends, and Notre Dame football weekends bring traffic jams across the whole north side. The older neighborhoods near downtown have narrow streets and alleys, while the outer areas have driveways and attached garages. After a heavy snow, plows clear the main routes first, so side streets in the older neighborhoods can stay rutted and slick for a while.
South Bend International Airport sits on the northwest side, and the South Shore Line runs commuter trains toward Chicago. Transpo runs buses through South Bend and Mishawaka, but the region is spread out, and the drive from Granger or New Carlisle to a shop takes a real chunk of the day. In lake-effect season, that drive can be slow and slippery, which makes a repair in your own driveway even more appealing.