You’ve been driving for a good chunk of the day, you’re pulling into an unfamiliar town, and you need a place to stay for the night. Happily, there’s a comforting sight just ahead—a motel with an illuminated “Vacancy” sign, the “No” thankfully darkened.

The “(No) Vacancy” sign, a beacon of hospitality and/or disappointment, has greeted road-weary American travelers for generations. But just as paper maps and toll booth clerks increasingly seem quaint relics of the analog age, the classic “(No) Vacancy” sign may soon become another victim of shifting travel habits and market forces.

First, some quick historical context. It’s not clear who came up with the ingeniously simple pairing of “Vacancy” and “No Vacancy,” which allows the motel operator to simply toggle the “No” on or off, but it was probably sometime in the 1930s or before. (While the canonical example is neon, electricity isn’t required: Some motels instead gave the “No” a cover-up flap or a slider panel.) By 1946, the signs had become so ubiquitous that country singer Merle Travis recorded a song called No Vacancy, which reached No. 3 on the country charts. America’s postwar boom in the 1950s and ’60s, which led to an explosion of automotive travel and a corresponding spike in roadside lodging development, further solidified the “(No) Vacancy” sign as a staple of American travel culture.

But a lot has changed since those days. “We don’t really have any customers who want that type of sign anymore,” said Alex Lauretano of the Lauretano Sign Group, a leading sign manufacturer for the hospitality industry. “At one point they were useful — but not anymore, with online booking.” Julie Hall, a spokesperson for AAA, which inspects and rates motels, confirmed that vacancy indicators are on the wane and also cited online booking as a key factor.

What about the freewheeling road trippers who don’t book days in advance and simply follow their wanderlust? Even that type of traveler can now use smartphone apps, or simply Google lodging options in the next town down the highway and call ahead to check on availability, rendering the “(No) Vacancy” sign somewhat moot.

The digital revolution isn’t the only threat to vacancy indicators. Another factor is the dwindling number of independent mom-and-pop motels and the corresponding growth of chains such as Days Inn and Super 8. “The chains tend not to have these ‘Vacancy’ signs,” said Jefferson Rogers, professor of geography at the University of Tennessee-Martin and co-author of The Motel in America. “They want you to walk in not knowing whether a room is available. So if they’re full, they can send you to another one of their properties in the vicinity and keep the business in-house. It’s a strategic decision.”

In addition, Rogers said, omitting vacancy indicators allows for overbooking (“If it’s late and you’re fully booked, but someone with a reservation hasn’t shown up, you can sell the same room twice”) and gives managers wiggle room when sizing up questionable customers. “If people come in asking for a room, and you think they look like trouble—rowdy college students, say—if you have ‘Vacancy’ out there, you’re kind of obligated to give them a room,” he said. “Without the sign, you can just say, ‘Sorry, we’re full,’ even if you’re not. That’s why you’re seeing fewer and fewer of these signs. They’re figuring out that they’re better off without them.”

Some chains have had other reasons for avoiding vacancy indicators. Legendary hospitality pioneer Howard Johnson, for example, forbade their use in his eponymous hotels, which began appearing in the 1950s. “He thought ‘Vacancy’ signs were downmarket,” said Rich Kummerlowe, a travel historian who runs a website devoted to roadside food and lodging. “Not having them was a way to differentiate the Howard Johnson’s properties from the mom-and-pops.”

Despite all this, the landscape is still dotted with countless vacancy indicators that were installed decades ago, and many motel owners still use them, at least for now. Some operators have even put their own spin on them. At the Best Western Plus Humboldt House Inn in Garberville, Calif., the sign says, “Vacancy” when rooms are available and “Full House” when the place is booked. (Best Western properties, unlike most chain motels, are independently owned and operated, so owners are free to have vacancy indicators, if they wish.)

The “Full House” message was the idea of Jim Johnson (no relation to Howard Johnson), who built the motel in 1984 and co-owns it today. “The theme we wanted was to have a warm and friendly atmosphere, so I came up with that ‘Full House’ thing,” he said. “It’s so much nicer than the typical ‘No Vacancy’ signs.”

While Johnson’s sign is unusual, it is not unique—“Full House” indicators can also be found at motels in Nevada, Utah, and elsewhere—nor is it the only alternate wording. About 150 miles to the north, Crescent City, Calif., is home to three aquatically named establishments—the Bayview Inn, the Lighthouse Inn, and the Oceanview Inn—all of which have signs that say, “Welcome” and “Sorry.”

“I just thought it was more inviting than the standard signs,” said Eileen Brown, who owns the three Crescent City properties. One of her managers, Margie Ludemann, said the alternate wordings have been good for business. “I’ve had some guests who’ve said that’s why they stopped here, because they saw the ‘Welcome’ sign, and it made them feel, well, more welcome to come in.”

There are still other variants. A smattering of motels simply use “Yes” and “No” (the austere “No,” unaccompanied by the usual “Vacancy,” seems a bit harsh, almost like a negation of the traveler’s search for shelter), and an AAA inspector recalled seeing a sign in Maine that said, “Happily Full.”

No matter what the wording may be, vacancy indicators face yet another challenge: neon maintenance. “There are very few people who repair neon anymore,” said Eric Johnson (no relation to either Howard Johnson or Jim “Full House” Johnson), owner of the Acorn Ridge Motel in Princeton, Wisc., which has a standard “(No) Vacancy” sign at the roadside. “I had one guy, but he recently retired, so I had him make me two of every letter, just in case something happens.” Other owners expressed similar laments about their neon vacancy signs.

It’s worth noting, however, that not everyone in the lodging industry is all that concerned about the current state of vacancy indicators or the prospect of their demise. Several motel owners contacted for this article seemed disinterested in the topic. One responded by asking, “What the hell kind of story to write is that?” and then hanging up. Which just goes to show that hospitality is where you find it, no matter which sign, if any, is illuminated out front.

©2016 Bloomberg L.P. This article was written by Paul Lukas from Bloomberg and was legally licensed through the NewsCred publisher network.

Photo Credit: The Lake Motel in Oregon. Motel vacancy signs are slowly disappearing as more motel guests look online first to check for vacancies, instead of driving by and deciding where to stay while on the road. Waywuwei / Flickr