Checking into your hotel late and tired sometimes means the depressing last, best option for food is the vending machine next to the ice machine.
Marriott is taking advice from its guests and experimenting with an unexpected twist in its lobby: a salad vending machine.
"Consumers are trained not to expect fresh food out of a vending machine," said Dave Henkes, vice president at the food industry research firm Technomic. "There's going to be a natural aversion."
But in Chicago, where a test has been underway for a week, guests are willing to give it a try, said Katie Krum, director of digital marketing at Marriott Hotels.
"The leap is difficult when you hear about it in concept," Krum acknowledged. "But once you see it, that leap really happens."
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What guests see is not a regular vending machine, but a kiosk of colorfully layered salads, stocked fresh daily by Chicago start-up Farmer's Fridge. Offerings include a "Detox Salad" with organic kale, quinoa, fennel, fruits and beans served in white balsamic vinaigrette. The company already operates 11 other kiosks in the Chicago area, focusing on local and organic ingredients with the relatively new SPE Certification for nutritional quality.
The offerings are made fresh each morning and the machines are cleared out and stocked with new items at 10 a.m. Unsold items go to a local food pantry, according to the Farmer's Fridge website.
Salads, breakfast items and snacks are pricedfrom $3 to $12. Protein add-ons for the salads, such as lemon-pepper chicken, can be purchased separately from the kiosk. The salad vending machine will be in the Chicago Marriott O'Hare for the next five months for testing with guests.
The experiment could prove beneficial to the vending business, which is struggling to move away from soft drinks and sugary snacks, to meet the needs of consumers increasingly looking for fresh, natural, healthy and organic offerings, Henkes said.
"Healthy food options are a growing trend, especially for the business traveler," he said. "Food and beverage is certainly a differentiator for a lot of hotel chains" and many of them are already cutting back room service hours as revenues are dropping in that category, he said.
But for Marriott, room service isn't going away. "It's not a replacement for room service at all, it's added value," Krum said.
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The idea for the vending machine was submitted to Marriott's "Travel Brilliantly" campaign by Anjana Kallarackal, a 21-year-old college student. The next winning idea from that campaign—power cubes in lobbies to quick-charge electronic devices—will roll out later this month, Krum said. The hotel chain is also working with the MIT Mobile Experience Lab to reinvent the hotel lobby as a social hub via a mobile app to connect people with similar backgrounds and interests.
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—By CNBC's Amy Langfield. Follow Road Warrior on Twitter at @CNBCtravel.