I have worked downtown for 20+ years and the downtown tunnel system is one of Houston's greatest assets. I don't remember how extensive the network was in the 1980's, but I remember parking in the Hyatt garage and tunneling to work. The tunnel network is huge today and it is the ultimate in "walkable". One of my employees lives downtown and tunnels to work in bad weather. For those who are searching for large pedestrian crowds street-side to get that "Big city" feel ..(why he asks???), just visit the tunnel system on a cold rainy day about 11:30. It is wall to wall people in a NYC stride. But if the weather is decent, during lunch I will go for extended walks street side and head for Sam Houston/Buffalo Bayou parks. A beautiful area that is under-utilized by downtowner's. If you have never made the trek... visit the tunnel system and marvel at the underworld.