Why Google Maps Can Underestimate Seoul Subway Travel Time
← Back to Complete Korea Planning Guide (2026)
← Back to Getting Around Seoul
Two Routes Show the Same Travel Time on Google Maps. One Arrives Noticeably Earlier.
This is a common experience for travelers navigating Seoul's subway system for the first time. Two route options appear with nearly identical estimated travel times. Both involve a similar number of stops. One is chosen more or less at random — and it takes significantly longer than the map suggested.
Google Maps estimates rail travel time accurately. Where it consistently underestimates is inside the stations themselves. The app models the train segments well, but cannot fully capture the corridor walking, vertical movement between underground levels, and platform waiting that happen between one train and the next. In large interchange stations, these internal movements add 5 to 15 minutes that the estimated total doesn't reflect.
What Google Maps Calculates and What It Misses
Navigation apps build subway route estimates from three components: the time spent on the train itself, the average frequency of trains on each line, and a standard assumption about how long transfers take. The first two are calculated accurately — Seoul's subway data is well-documented and train intervals are consistent enough to model reliably.
The transfer assumption is where the gap appears. Google Maps applies a general transfer estimate that works well for simple exchanges between adjacent platforms. In Seoul's larger interchange stations, transfers are not adjacent platform exchanges. They involve walking 300 to 600 meters through underground corridors, changing levels by escalator or stairs, reading directional signs at multiple intersections, and then waiting for the next train on the new line. A general transfer estimate of 3 to 4 minutes doesn't capture this. The real movement often takes 8 to 15 minutes.
The practical consequence is that two routes showing the same total estimated time can produce very different arrival times when one involves a major interchange station and the other does not.
Why Seoul's Major Stations Produce the Largest Gaps
Seoul's interchange stations are physically large because they were expanded incrementally as new lines were added to the network across several decades. Lines built in different eras connect to each other through underground corridors rather than through a unified station design, which means the walking distance between platforms at major interchanges can be as significant as the train ride itself.
At Express Bus Terminal Station, transfers between Line 3, Line 7, and Line 9 require walking through long underground corridors before reaching the next platform — a process that typically takes 7 to 10 minutes on its own. At Dongdaemun History and Culture Park Station, multiple lines intersect in a large underground complex where corridor walking and passenger density during peak hours extend the transfer significantly beyond what any app suggests. At Seoul Station, passengers changing between subway lines and rail services often navigate several underground levels before reaching the correct platform.
In each of these cases, the station looks like a single node on the map. Inside, it behaves like a separate journey segment between the two train rides.
How Large the Gap Actually Is
| Transfer type | Google Maps estimate | Typical real duration |
|---|---|---|
| Simple platform-adjacent transfer | 3–4 minutes | 3–5 minutes — reasonably accurate |
| Medium interchange station | 3–5 minutes | 7–10 minutes |
| Large interchange station | 5–8 minutes | 10–15 minutes |
| Complex multi-line transfer at peak hours | 5–8 minutes | 15–20 minutes |
For a route with one transfer at a large interchange station, Google Maps may underestimate total travel time by 5 to 12 minutes. For a route with two such transfers, the underestimate can reach 10 to 20 minutes — enough to miss a fixed appointment or arrive at a KTX departure with less buffer than planned.
How to Adjust for the Gap When Planning Routes
The most reliable adjustment is to prefer routes with fewer transfers when two options show similar estimated travel times. The transfer count is visible in Google Maps and Naver Maps before committing to a route. A route with one transfer and 28 minutes estimated travel time will almost always arrive before a route with two transfers and 25 minutes, once the real station movement at the second transfer is accounted for.
A second adjustment is to add 5 to 10 minutes of buffer per transfer when the route passes through a station known for long interchange corridors. Express Bus Terminal, Dongdaemun History and Culture Park, and Seoul Station are the most common examples for first-time visitor itineraries. Any route that passes through these stations as a transfer point should be assumed to take at least 5 to 8 minutes longer than the app suggests.
A third adjustment applies specifically to time-sensitive journeys — KTX departures, tour pickups, restaurant reservations. For these, the reliable rule is to plan as if each transfer at a major interchange station will take twice as long as the app estimates. This produces a conservative total that is almost never wrong.
When the Gap Changes the Transport Decision
For most leisure journeys during flexible daytime hours, the gap between the estimate and reality is an inconvenience rather than a problem. The journey takes longer than expected, nothing is missed, and the next plan adjusts naturally.
The gap becomes material when the route involves two or more transfers, one of which is at a major interchange station, and when a fixed arrival time is involved. In these specific situations, a direct taxi — which has no transfer movement at all — may produce a more reliable arrival time than the optimistically estimated subway route, even if the fare is higher.
Related Guides
→ Why Seoul Subway Transfers Often Take 15–20 Minutes
→ Why a 10-Minute Seoul Subway Transfer Can Turn Into 25 Minutes
→ Why Seoul Travel Takes Longer Than Expected
📚 More from Getting Around Seoul
Browse all guides in this category: Getting Around Seoul →