At noon, when the downtown area's growing number of office towers begin to empty, the sidewalks quickly clog with pedestrian traffic. But so do the underground walkways as well.
Thousands of the city's office workers simply opt to take the below-ground network of tunnels to a restaurant, a store, or whatever their destination happens to be at the time.
These subterranean passageways, which are rapidly growing in number and which someday may link large areas of the downtown, offer climate-controlled comfort. Also, they provide a second tier of shops and places to eat.
Moreover, the complex of tunnels, someday to be augmented by a major network of skywalks, is bringing relief from street-level pedestrian crowds to an increasingly congested downtown area. Pedestrian competition at street intersections can raise havoc with downtown truck and auto traffic.
Thus, the tunnels are doing a good job. Aside from speeding up vehicle traffic, they offer the walker more rapid travel, free from the interruptions of traffic lights, and welcome relief from the searing heat of summer. Temperatures here of 100 degrees F. and higher are not uncommon.
Dallas, of course, is not the only US city to attempt to link its downtown with tunnels and bridges. Cincinnati, for example, also has a growing skywalk network.
But Dallas does have an advantage over most other cities with similar plans. The city's enormous growth, much of it concentrated downtown, offers the opportunity to build these amenities as new buildings go up.
Developers simply include the underground tunnels in their plans, which is far easier than trying to build them after the major structures are set in concrete.
Michael Finley, an urban planner for the city, declares: "Every time a new building is built [the tunnel] is added in almost automatically."
The giant Republic Bank, with adjoining towers of 36 and 50 stories, plans its second underground tunnel to connect with Dallas Center, the first phase of which has been built nearby. Its other link connects it with Thanksgiving Square, which is surrounded by a growing complex of major buildings, including the headquarters for LTV Corporation and an operations center for Atlantic Richfield.
Republic's project is but one example of corporate support for the system, which was first proposed in a 1950s traffic report. Today it is growing rapidly with a financial boost from the city.
The city's policy provides developers with the use of city-owned rights of way free of charge if they put in climate-controlled above- or below-ground links. The city also has agreed to pay one-third of the cost for sections over or under public land. Building developers pay the rest.
Money sometimes presents a problem. As an example, the city failed to build a link between its stunning new city hall and a new library now under construction across the street. "The funding just didn't come through," says Mr. Finley.
There are other problems as well. The location of sewers means that some of the tunnels have to begin too far below ground to be economically feasible. The solution in these cases, adds Mr. Finley, is to build above- ground links.
Further, there are aesthetic questions to be considered. While appearance is less important when a passageway is going underground and the exterior is invisible, skywalk links raise an important issue: Should the skywalk be compatible with the buildings it joins? Mr. Finley says city planners are likely to recommend a compatibility requirement.
One problem is probably more amusing than anything else. Underground passageways present a new landscape for those who are unfamiliar with them. Although they are marked with directions, some travelers nonetheless do get lost.
These difficulties aside, this city's downtown daytime working people, numbering 120,000, have found underground travel to their liking, by and large. Mr. Finley concludes: "The city estimates right now that well over half the people who can use the network do use it."