This true story about interaction design gave me some insights into ride-hailing apps. It all started with my old roommate.

The Roommate

We called my college roommate “Boss” – he was assertive, thought differently, and often dropped unexpected truth bombs. He’s an embedded systems engineer, utterly obsessed with the field. He’s also a hardware whiz.

Around 4 PM, he used Didi (China’s Uber) to visit me for dinner. He lived about 6km away. We hadn’t seen each other in a while, so we had a lot to catch up on.

We started talking about a classmate’s wedding, and the conversation naturally drifted to his area of expertise. He went on about algorithms, development philosophies, different ways to control electric motors, and even battery management systems for electric cars. That’s just how he is. He knows I don’t get most of it, but he keeps going, regardless. Even though I only grasped the basics, I listened patiently. His passion is infectious; it’s not painful to hear him talk about this stuff. He reminds me of my calculus professor, who would pause mid-lecture, reflect, and exclaim, “Isn’t the proof of this equation beautiful!” I hated that class, but I respected that professor.

Our major was electronic information. Maybe less than 10% of the class understood the core courses, and we were both in the majority. In our senior year, it was like a switch flipped. He suddenly became super interested in our major, catching up on previous courses and studying beyond the textbooks. He later told me he finally saw how this knowledge applied to real projects – it was actually useful! That’s when his passion ignited. With his dedication, I’m sure he’s a big shot in the industry now.

But he’s clueless about internet products. He still uses an iPhone 4, with very few apps, all on one screen. No folders, no icon organization, and the dock still has the four default iOS apps. It shows that even someone as studious as him won’t waste time on things he doesn’t care about.

I asked if he took a regular ride or carpooled (I wasn’t precise, because I also use Uber, so “regular ride” meant Didi’s Express option). He wasn’t sure, saying it was probably a regular ride since there were no other passengers. I asked the cost, and he said 14 yuan.

After dinner, around 9 PM, he used Didi to head back. I watched him, and noticed a few interesting things:

Calling a Ride

He first tried hailing a taxi, hesitated, then tapped “Hitch” (carpooling). Realizing I was watching, he asked, “Should I choose Hitch?”

I suggested Express, thinking it was what he used to get here, and it would be familiar.

He selected Express and entered his destination. He hadn’t set “Home” or “Work” addresses, so he had to type it in. He tapped the pickup location first, but didn’t realize it.

As he was about to enter his home address, I pointed it out and gestured to the text prompt: “Where are you?”.

He backed out, tapped the destination, but then realized he didn’t remember the exact address. So he backed out again, tapped the top-left menu, and went to “Trips.” He tried to copy the pickup address from his earlier ride, but couldn’t.

He went back to the ride-hailing screen and typed in his home address. The list showed several results: shops, bus stops. He just waited. I didn’t say anything, observing.

But his eyes had left the phone, and his hand lowered. He thought he’d successfully called a ride.

I had to tell him again to choose an address to confirm his destination.

He picked a bus stop, tapped “Call,” and finally got a car.

However, his Express ride back, without carpooling, only cost 5 yuan. So I guessed he probably didn’t take Express on his way here.

The Problem

After he left, I wrote down the process. Thinking about his actions and mindset, I had some insights.

His ultimate goal was to go home. Unsure how the app would react, he assumed it would understand his intentions like a real person. Since you picked me up from home earlier, you should know where my home is, and I want to go back there. His struggle to copy the earlier pickup address clearly showed his goal: a return trip – going back where he came from.

But reality wasn’t perfect. Even a real person can’t always understand another’s thoughts.

The gap between the result and his expectation created a problem. The root cause wasn’t that he didn’t remember his address; it was that he thought Didi should know his home, but it didn’t. The “Home” and “Work” addresses are designed to solve this. However, few people proactively set these, even some IT professionals.

This got me thinking. Aren’t these two separate issues?

1. Didi can’t intelligently know or guess my home.
2. Didi doesn’t offer a convenient return trip option.

In my roommate’s case, “going home” and “return trip” overlapped. But they’re not always the same, so let’s consider them separately:

Going Home

From a mental model perspective, going home is switching between “at home” and “outside.” Calling a ride to leave exits the “at home” state. Until you step back inside, you’re “outside.”

For example, if someone gets a call about a package while they’re out, they’d say, “I’m not home,” or “I’m out, please leave it with management.”

“Outside” is uncertain, but “home” is relatively fixed. By analyzing historical trips, visit frequency, and arrival times, it should be possible to guess. For users without set addresses, if the app detects frequent trips to the same area, it could prompt: “We noticed you often go to [location]. Is that your home? Or work?” Recommendations and guidance could encourage users to set addresses, making future trips easier.

Return Trip

Is a return trip common? I don’t have the data. But this scenario is typical: going from home (or work) to a place for leisure or errands, and returning the same way on the same day.

If it’s between two frequent places, “return trip” doesn’t quite fit. We’d think “going home” or “going to work,” part of our routine. A return trip implies a temporary, less frequent location, subconsciously feeling like a short “business trip” or “outing.” Like people going home for the holidays; when it ends, we need a “return” ticket to the city we live in. The destination doesn’t matter; the key is that having come here, we can get back. The “return trip” concept becomes clear.

But a meaningful “return trip” concept doesn’t mean a “return trip” feature is meaningful. The most obvious approach is a “Return Trip” button on the main screen, allowing a one-tap ride to the last trip’s starting point. But there are problems. What if the user hailed a taxi on the street? Or got a ride from a friend? The user wants to go back; they don’t care how they got there. The app can’t know this, so a return trip option would just add confusion.

The key issues are:

1. How can Didi track user travel history using other methods?
2. How can Didi know if a destination is temporary?

A mobile app alone can’t solve these. Therefore, the “return trip” concept might be meaningful, but it’s not something a single mode of transportation can provide.