However, some traffic improvements, such as a left-turn signal on 400 West to allow northbound vehicles to head west on Parrish Lane, will have to wait until actual counts of traffic accessing the big box can be charted.

"We need a certain number before we can install a signal," said UDOT spokesman Adan Carrillo. "Right now, we don't have the results that would warrant the need for a particular signal there."

But he added: The expected traffic swarm at Centerville's Wal-Mart "is on our radar."

Centerville City Manager Steve Thacker expressed gratitude that UDOT had expedited several millions of dollars in improvements to the Interstate 15 interchange at Parrish Lane in advance of Wal-Mart's grand opening.

Now he hopes UDOT officials will be similarly speedy with the new traffic tally, which he predicts will produce numbers that warrant the left-turn signal.

"I'm confident that intersection will be a real mess," Thacker said. "We'll have to override the situation at peak times with manual controls" - police officers directing traffic flow.

Studies conducted in 2004 projected that Wal-Mart would boost Parrish Lane traffic by 15 percent, Thacker pointed out.

At an August City Council meeting, Wal-Mart Manager Amy Teichert said the new 24-hour center, fully-staffed, will employ 425 sales associates. Trucks began unloading merchandise a month ago to stock the miles of shelves in the giant one-stop shop.

In recent months, with Wal-Mart's grand opening on the horizon, Centerville asked UDOT to make an exception to its policy to wait until after opening to determine traffic patterns.

"Our traffic studies indicated that left-turn signal would be needed, and Wal-Mart said they would pay for signal improvements," Thacker said. "But [UDOT] held firm."

Now he suspects that actual improvements could be several weeks out, as traffic counts would be over-inflated during the store's first week of operation.

To Wal-Mart's credit, he said, pedestrian-friendly features were incorporated into the Centerville site, including portions of a trail that connect to a densely populated, multifamily development.

Said UDOT's Carrillo: "People need to be sensitive to their surroundings and be careful and respectful of others."

cmckitrick@sltrib.com