The specific thing about a commute is that it's dead time by design — nothing else is expected of you, which makes it the path of least resistance for a phone to fill entirely, by default, without anyone consciously deciding that's how the time should go. A twenty-five minute train ride reading a book, learning a language, or just thinking is a very different twenty-five minutes than the same ride spent scrolling, but the phone requires zero decision to fall into and the alternative requires an actual choice, made fresh, every single trip. There's also a specific psychological pull at play on a commute: the environment is unfamiliar or repetitive enough that boredom sets in quickly, and unlike boredom at home, there's usually no easy alternative activity readily available besides the phone already in your pocket, which makes it the default almost by elimination.
What you've probably already tried
Bringing a physical book on purpose, downloading a podcast or audiobook in advance so there's a ready alternative, deleting the worst offending app before a commute-heavy week. These work on the days the alternative got prepared in advance, and fail on the far more common days it didn't, when the phone is the only option immediately available and takes precedence by default. Some commuters try alternating between a book and the phone by rule — one day each — which introduces some variety but doesn't actually change what happens on the phone days, and over time the phone days tend to become the default while the book stays unread in a bag. Audiobooks and podcasts downloaded in advance specifically for the commute tend to work better than in-the-moment decisions about what to listen to, since removing a choice at the point of use reduces the friction of the better alternative rather than just the worse one. Downloading a few episodes or chapters the night before removes the one decision most likely to default to scrolling instead.
Why generic blocking advice fails specifically here
"Read instead of scrolling" is good advice that assumes a book is already in hand; on the actual day, tired, running for a train, the phone is what's already in your pocket, and defaulting to the thing that's already there rather than the thing you'd have to remember to bring is exactly what happens without friction pointing the other way. It's also worth noting that commute time is one of the few truly recurring, predictable windows most people have every single working day, which makes it a genuinely valuable slot to protect — small, consistent gains here compound meaningfully over months in a way that occasional, one-off focus sessions don't. It's also worth noting a standing commute versus a seated one changes what's practically possible — reading is harder standing on a crowded train, which is worth factoring into what the realistic alternative to scrolling actually is on a given day. Standing commutes in particular narrow the realistic list of alternatives worth planning around in advance.
The honest fit
A quiz-gated block fits a commute well because it's a short, fixed window where a small amount of friction goes a long way — raising the cost of the automatic scroll by even a little is often enough to tip the choice toward whatever the actual intended alternative was, especially over a recurring, twice-daily window where the habit compounds either way. It also travels naturally across different commute types — train, bus, walking with headphones in — since it doesn't depend on a particular environment or app-switching pattern, just the same friction applied consistently to whichever app tends to fill the time on a given day. It also requires no extra gear or preparation, which matters for a habit that needs to survive the days nothing extra got packed or downloaded in advance. That consistency across contexts is part of why a commute is such a reliable place to apply this kind of friction.
Where it isn't the right fit
If the commute is the only real downtime in an otherwise packed day, blocking every distracting app during it may just replace scrolling with staring at a wall, which isn't obviously better — some genuinely restful low-effort phone use is fine, and the honest goal here is redirecting a habit, not eliminating rest entirely. It's also fine, and probably healthy, to let a short commute simply be a low-effort mental break some days — the goal here is redirecting a habit that's eating into something you'd rather be doing, not treating every unstructured minute of the day as something that must be optimized. Weather, crowding, and simple tiredness all affect what a commute can reasonably be used for on a given day, and it's fine for that to vary rather than aiming for the same ideal every single trip. There's no need to optimize every single trip equally to see a real benefit over a few months. Some days the honest, healthy choice is just resting, not optimizing the commute at all.