Road Worrier: Road geeks quibble over I-495 numerical name

Alarm bells were rung and harrumphs were harrumphed a few weeks ago after Gov. Pat McCrory announced that U.S. 64 will be elevated in status between I-440 in Raleigh and I-95 in Rocky Mount – and rechristened Interstate 495.

Oh, it’s fine, the alarmists said, to dress up an old freeway with new blue interstate shields. But don’t those people at the state Department of Transportation know the rules? How dare they name it 495?

The Road Worrier strives to stay ignorant on subjects that just do not matter in this world. When it comes to the deep import of “twerking,” for example, he is happily shallow.

And there are perhaps more twerkers – sorry, is this correct usage? – around Raleigh than there are folks who fret about the rules for naming interstate highways. But it turns out that this arcane issue truly does matter to a bunch of people who registered their objections to “I-495” online, in letters to the editor and at a road-geeks (as they call themselves) website.

“Someone at NC DOT needs to learn how to number an Interstate,” Bob Cottone of Raleigh commented on an N&O story about this issue. “Circumferential routes around cities should start with an even number (e.g., I-440). Spur routes should start with an odd number (e.g., I-581). So I-540 should really be I-240, I-640 or I-840. The new I-495 should really be I-195, I-395, I-595 or I-795.”

Got that? Cottone was not alone in grumbling about proper initial numerals for Raleigh’s old 540 Outer Loop as well as for the new I-495.

“Of course, to many drivers, the route numbers mean little,” wrote Ken Thorn of Carrboro. “ ... But to those who can read and understand map routes, why deviate from an established and explainable standard?”

(Note to non-geeks: You can stop reading here. Keep twerking and carry on.)

The threefold answer Thorn’s question is: (1) The feds’ rules for interstate numbers are complicated; (2) the feds do not explain them clearly, and (3) the feds blithely break their own rules, anyway.

Logical to a fault

I-95 is, in geek-speak, the “parent” route for a road such as I-495. The Federal Highway Administration website says this three-digit route name must start with an odd number if it is a “spur route” connected to the parent route only at one end. An example of this is I-795, which starts at I-95 in Wilson and ends at U.S. 70 in Goldsboro.

But that first digit is supposed to be an even number if the offshoot loops back to reconnect with the parent route. That’s what happens with Raleigh’s I-440: It connects with I-40 at both ends.

The FHWA also makes that first digit an even number when it names “connecting Interstate routes.” Wait, what does this mean?

“It’s anything that connects two interstates,” says Kevin Lacy, DOT’s chief traffic engineer. “Basically, if there’s an interstate on both ends, then it would be an even number.”

And since it will connect I-440 to I-95, the new interstate is not a “spur” after all. So it will properly be called I-495.

Down the road

Actually just the first four miles, I-440 to I-540 in East Raleigh, will receive this name right away. The remaining 41 miles through Wake, Franklin and Nash counties will be called “Future I-495” until the state upgrades the rest of U.S. 64 to full interstate standards. There’s no timetable for these improvements, but DOT figures the work will cost about $40 million.

Does that settle everything?

Sorry, not quite. Let’s take care of two more items and then agree never, ever to discuss these matters again:

•  DOT originally asked the feds to authorize a new interstate from Raleigh through Rocky Mount and all the way to Norfolk, Va. There was talk of calling it I-44. There’s still a lot of interest in this full route.

But it will take years of planning and consultation with Virginia officials to get a new interstate between Rocky Mount and Norfolk. For the time being, it’s easier to get federal approval for the shorter section from Raleigh to Rocky Mount – and for the longer three-digit name.

•  The Outer Loop formerly known as I-540 will no longer be a spur, because it will connect I-40 at one end to I-495 at the other. So the feds’ rules will require that it be renamed I-640, right?


DOT favored the name I-640 more than 20 years ago when it was preparing to build the loop around our city, starting at I-40 near Research Triangle Park. But the feds were not persuaded back then that the new freeway would ever extend farther across North Raleigh than U.S. 1. So they called it a spur whose three-digit name must start with an odd number.

Now, as noted in Cottone’s comment, it’s appropriate to rename the loop I-640. But the state DOT no longer prefers this name. So, as they’ve done with “connecting interstates” in Pennsylvania and New York, the feds have agreed to ignore this rule.

When DOT officials requested a waiver from the feds’ renaming requirement, they cited “public expectation, historic controversy, and economic burden of sign replacement.” Of course they weren’t talking here about road-geek expectation.

Most drivers would find it confusing and wasteful to rename I-540. They would perhaps express their opinions by twerking in the streets, whatever that means.