Can a Voice AI Drive-Thru Become Your Best Order Taker?

“Heads up, AI is giving us a hand today” reads the label on the drive-thru speaker. Does that make you feel confident, or uncomfortable? Afterall, it is for the meal you were eagerly waiting for.

Voice AI is stepping in to speed up service, smooth out operations, and keep drive-thru lines moving faster than ever. With the restaurant AI market expected to soar from $9.68 billion in 2024 to $49 billion over the next five years, it’s clear this isn't a futuristic experiment anymore. It’s happening now, and the big brands are onboard.

But is Voice AI delivering on its promise? And if it is…at what cost?

Our 2025 Emerging Experiences Study hit the ground running, mystery shopping real AI-enabled drive-thrus at major brands to find out.

The result?

Some seriously impressive wins... and a few moments that still made guests reach for patience instead of their fries.

Want a summary of all the key takeaways from our study?
Read our latest blog on the Emerging Restaurant Trends for the whole breakdown.

The Promise of Voice AI Drive-Thru

Voice AI is about an operational lift. The pitch is simple:

• Shorter lines
• Faster service
• Reduced labor pressure
• More consistent performance

That’s why brands like Taco Bell, Wendy’s, and Bojangles have rolled it out in their drive-thrus. Guests speak to an automated system that takes and processes the order, freeing up staff to focus on food prep and delivering great service at the window.

And the potential goes beyond the speaker. According to QSR Magazine, some Voice AI platforms are helping restaurants optimize labor by adjusting staff schedules in real time based on drive-thru traffic. That means cutting back during slow stretches and ramping up just before the rush hits—a win for the overall customer experience. 

So, we took a closer look. In January 2025, our mystery shoppers hit the road to evaluate Voice AI performance firsthand, placing real orders with real customizations and timing every moment from hello to handoff.

Let’s break it down.

Where Voice-AI Impressed

Brands testing AI drive-thru tech are seeing real shifts in the food ordering experience. Across Taco Bell, Bojangles, and Wendy’s, Voice-AI brought improvements to speed, clarity, and friendliness, especially compared to legacy drive-thru models. Here's what caught our attention: 

Speed That Operators Dream About
At Taco Bell, Voice AI cut total drive-thru time by 1 minute and 54 seconds compared to the 2024 benchmark, even with more cars in line. Wendy’s brought its total experience time well below the QSR average, showing that smart implementation can pay off.

Conversations Were Clear and Crisp
Speaker clarity came in near perfect across all three brands. At Bojangles and Taco Bell, shoppers reported 100% clarity from their AI order taker. At Wendy’s, it was just a tick below. Guests moved through their orders smoothly, with hardly any need to repeat themselves.

Shopper Insights:
"Ordering with the AI is great. Clear and easy to understand her voice."

Pickups Felt Warmer
Here’s where things got interesting. When AI took over the speaker, staff had more time to focus on the handoff—and it paid off. One brand clocked one of the highest friendliness scores in the entire study, jumping ahead of traditional formats by double digits. Turns out, the human touch still matters. Voice AI just helps make room for it.

Shopper Insights:
"The polite and friendly staff and the ease of picking up the food were the most memorable part of the experience."

Quality Held Strong Under Pressure
Worried that speeding up might mean cooling down? Not here. One brand nailed it with a 100% score in both food temperature and taste. Guests got their orders fresh and exactly as expected.

Voice AI Has a Sales Pitch
Voice AI isn’t shy about making recommendations either. In fact, suggestive selling happened in 81% of Voice AI drive-thru visits, outperforming the 2024 benchmark of 64% in traditional lanes. One brand really leaned in, offering upsells in 93% of visits!

The opportunity now? Build on what’s working and refine what isn’t. Curious which brands are finding that sweet spot? Download the study to find out!

Where Voice-AI Fell Short

For all the buzz and breakthroughs, even the smartest tech isn’t flawless, and the restaurant voice AI still has a few hurdles to clear before it becomes a no-brainer for every restaurant. 

Order Accuracy Lost Some Ground
While overall satisfaction stayed high, accuracy was a different story. Traditional drive-thrus got the order right 89% of the time. With Voice AI, that number dropped to 83%.

And here’s the real kicker. 65% of those errors were tied to one thing: Customizations. When shoppers tried to modify their orders ("extra sauce," "no pickles," "light ice"), the AI ordering system often struggled to keep up.

Shopper Insights:
"When ordering a soft drink, I attempted to select light ice for Dr. Pepper but received a message stating the option was unavailable. It caused the drink to be removed from my order, requiring me to reorder it."

AI Took the First Swing, but Sometimes Needed Backup
Voice AI handled the conversation... most of the time. But not always.

Across the board, nearly 1 in 4 drive-thru orders still needed a human to step in. Whether it was to clarify a customization, fix a hiccup, or save a fumbled interaction, the baton had to be passed back.

But here’s what’s really interesting: one brand kept intervention almost nonexistent, clocking just 3% of visits needing employee involvement. That’s a serious standout, and a sign that the handoff between humans and machines doesn’t have to be clunky. But that same brand missed the mark on accuracy—scoring 11 percentage points below the benchmark. Proof that when it comes to Voice AI, there’s still plenty to figure out.

Grab the 2025 Emerging Experiences Study to see which brand nailed the hands-off handoff, and which ones still call-in backup more than they’d like.

The Tone Dilemma
One brand had 67% of shoppers call the experience “easy and smooth” — the highest score of the bunch. But here’s the twist: that same brand scored 19 percentage points lower than the friendliness leader when it came to the AI’s tone. Interestingly, that wasn’t by accident. This brand intentionally opted for a digital voice designed to clearly signal that guests were interacting with AI. It was a strategic move to maintain transparency and stay true to brand expectations.

It’s a bold choice, and it opens up a bigger conversation: can Voice AI sound robotic and feel friendly? More on this in our latest webinar with QSR Magazine.

Shopper Insights:
"I was looking at the menu to decide which items to order, and AI kept asking every few seconds what I would like to order. It was kind of pressurizing."

Voice AI is making serious moves, but it’s not flawless.

Want to know who nailed the balance of brains and charm? The full rankings are in the study.

Discover other drive-thru trends top QSR brands are betting on—insights from our
Annual Drive-Thru Study.

Before You Scale Voice AI, Here’s How to Measure It Right

Mystery Shopping: The Guest’s View, Unfiltered

Think of mystery shopping as your reality check. It’s not just about spotting glitches, but about capturing how Voice AI performs from the speaker to the pickup window, across locations and dayparts.

With targeted restaurant mystery shops, you can uncover:

• All angles of the AI experience through the customer lens.
• Unbiased, third-party insights that catch what internal teams often miss.
• How the interaction felt: was it friendly, smooth, frustrating, forgettable?
• The real impact of a new technology on the overall guest experience.

Mystery shopping opens a world of insights you can’t afford to miss when stepping into something as bold and complex as a voice AI drive-thru. Discover how mystery shopping programs can reveal the real story behind your AI drive-thru experience.

Curious to know how to get started? Read more on the Key Steps to Launch a Mystery Shopping Program.

Survey Tool: The Fastest Way to Spot Friction

Your guests are already forming opinions about AI in your restaurants. You just need to capture them.

With quick, post-visit surveys, you can tune into what the experience actually feels like on the other side of the speaker. Was the process intuitive? Was the voice clear and natural? Did it feel like your brand?

Use surveys to:

• Hear what guests really think about your AI’s clarity and tone.
• Track satisfaction trends by store, daypart, or order type.
• Catch drop-offs in friendliness or ease-of-use before they become habits.
• Turn feedback into fast action, without waiting for a public complaint..

With a powerful survey tool, you can capture even the small insight that unlocks your biggest competitive edge.

Is Voice AI the Future of the Restaurant Drive-Thru?

Short answer: yes.
But it’s not the full story yet.

We’ve seen the promise, the pitfalls, and the potential of Voice AI in action. The brands leading the charge are learning, testing the tech under real-world pressure, and pushing the boundaries of what drive-thru can mean.

But without the right insights, it’s impossible to know where your system shines, or where it’s quietly falling short.
The 2025 Emerging Experiences Study breaks it all down: which QSRs are leading, what’s moving the needle, and where the next big leap is waiting to happen.

Want to know what it really takes to win with Voice AI in 2025?