Every night, I commute across the city to get home. It isn't a very long commute, but it involves bridges, rivers and tunnels.
A few nights ago, I snapped a pic because the road was pretty empty on my regular commuting hour. This is an sub-terrain highway that leads to the bridge.
Even the city in Pittsburgh doesn't feel very urban sometimes because it is nestled in a river valley. Green hills (except winter) and flowing rivers take the edge off the city. This area is one of the places where Pittsburgh can feel crowded and very urban.