oceanspray –
The 18th Street pedestrian overpass over the railroad tracks, and the connecting tunnel under Lake Shore Drive, are about as safe a way to access the Lakefront Path as exists anywhere in Chicago. The neighborhood at the west end of it is upscale residential. Just do the normal common sense things you would do in any big city. Be aware of your surroundings, know where you’re going, don’t wear headphones.
Once you get over the railroad tracks, and reach the bottom of the long ramp, you are not yet at the Lakefront Path. At the link is a map that will help with that. It just shows the short segment between the McCormick Place area and the entrance to the overpass (which has a nice little park with a “Battle of Fort Dearborn” historical marker), plus the bridge and tunnel themselves, plus the route from the other end of the tunnel over to the Lakefront Path.
http://www.gmap-pedometer.com/?r=3763763
When you get to the bottom of the ramp, turn right and go straight east through the tunnel under Lake Shore Drive. When you get to the east end of the tunnel, you’ll be facing the parking garage for Soldier Field. Turn left.
Run NE along the side of the parking garage, but don’t go straight through the next tunnel, that you can see Soldier Field on the other side of. Instead, bend right so you’re now running east along the north side of the parking garage. As the sidewalk you’re on begins to bend to the right, you’ll see a narrower paved walkway on your left, which has a water fountain on the left-hand side just after it turns off the sidewalk you’re on. Take that.
Follow it east across the four-way intersection (Museum Campus Drive – not busy). The Lakefront Path is just on the other side of Museum Campus Drive. Right is south; left is north. Either way is perfectly safe by the standards of any major US city, despite some of the more hysterical stuff elsewhere in this thread.
Once you’re on the Lakefront Path, even if you should happen to lose the path and either are completely lost or are just no longer sure you’re really on the “official” Lakefront Path (the signage is excellent in most places, but not all), there is no way you can really wander into a bad area. When you feel like you’re ready to turn around, just retrace your steps.
It’s a great city, and it has NOT suddenly become dramatically less safe. Welcome and have fun.