Hall of Infinite Doors

You wait until the highway is temporarily clear, and it takes over 30 minutes for a break in traffic to appear. You quickly then run out into the street and pry off the manhole lid with your hands, which to your surprise is extraordinarily light. You feel cool air, almost like it was out of a massive air conditioner blast out of the hole. You then shrug your shoulders and leap in. Your surroundings fade and you find yourself back in the hallway...