The state Department of Transportation last week erected signs renaming a 4.5-mile Outer Loop extension soon to open in western Wake County and Research Triangle Park.

DOT officials started building the $102 million freeway in 2004 as part of Interstate 540. They waited until late May to choose a half-new name: N.C. 540. The change is tied to a planned 18-mile toll road, opening in 2011, that will include tollbooths on a 3-mile stretch of 540.

As workers on N.C. 540 erected diamond-shaped state highway signs in place of red-and-blue interstate shields last week, they also were swapping numbers on green mileposts and exit signs.

They were fixing a 19-mile mistake discovered by Malme, a Duke University data analyst.

Malme blamed the goofs on poor internal communication within DOT. He recalled DOT's 10-mile paving blunder on I-40 -- the subject of a 13-month, $21.7 million repair job that will affect I-40 travel until May.

"Simply more communication between departments ... might have avoided these problems," he said by e-mail to the Road Worrier. "Though they aren't as bad as the botched paving job, [they] still cost taxpayers money and the delay in the use of [a] new highway."

Phillip Johnson, the DOT project engineer, said last-minute decisions to rename the road and replace its exit signs did not delay the opening of N.C. 540, expected late this week. The extra cost amounted to $13,200, he said.

Malme maintains Web pages exploring his fascination with arcane subjects including Red Sox baseball and future interstate highways. He told DOT in April that he suspected the 540 exit numbers, and their corresponding mile markers, were too low.

The mile numbers are supposed to track a complete, 360-degree Outer Loop -- something that may never materialize. Going clockwise around Raleigh, the numbering starts with zero at I-40 and reaches 26 miles at I-540's eastern end in Knightdale.

DOT's Geographic Information Systems staff reckoned that the odometer would hit 51 miles in the hypothetical future, when a finished 540 looped back to its origin at I-40. So the new interchange with N.C. 54, a mile southwest of I-40, was marked on big green signs as Exit 50.

But other DOT documents show the Loop length as roughly 70 miles, Malme pointed out.

He was right. DOT's GIS crew was wrong. That's why new mileposts and exit signs were installed last week to mark the three 540 interchanges this way: Exit 66 (N.C. 55), Exit 68 (Davis Drive) and Exit 69 (N.C. 54).

By whatever number, those new exits will be magnets for many 540 commuters who now clog the narrow I-40 exit ramps on weekday mornings. If you're among those affected, I'd like to hear from you -- before N.C. 540 opens for traffic, and after. See my contact information below.

Let's not get lost

"Wayfinding" isn't in my dictionary, but it has its own Wikipedia page. If you've ever tried to find your way to any part of downtown Raleigh, you know the opposite of wayfinding:

Lostgetting.

Maybe you have to find your way to the Wake County Courthouse, or you want to check out the new downtown coffee spots. You'd like to see Shaw University, Glenwood South or the N.C. Museum of Natural Sciences. Or you plan to visit the new convention center that opens next year.

You know the Beltline exit signs for downtown Raleigh are confusing. The direction signs on Wade Avenue and other inbound streets are few and microscopic. The availability of parking seems like a rumor.

Raleigh's Urban Design Center wants to help natives and out-of-towners find their way to downtown Raleigh attractions, distractions and parking spaces.

And it wants your ideas.

Read about the city's plans to improve wayfinding online at www.raleighnc.gov. Call Elizabeth Alley at 807-8477 or send e-mail to elizabeth.alley@ci.raleigh .nc.us.

Come to a wayfinding open house from noon to 2 p.m. Wednesday at the Urban Design Center, 133 Fayetteville St.

Call 'em if you get lost.