Lake Shore Drive is a north-south highway that runs along the edge of Lake Michigan. It's usually a good route between downtown and the Lake Michigan-bordering north side neighborhoods along with the North Shore suburbs. It also provides access to lakeside parks and beaches and Lincoln Park Zoo.
During a blizzard in 2011, the highway was shut down and some motorists were trapped in the snow for up to 12 hours with some requiring hospital stays. Here's an article about it.