Google Maps Japan has offered crowdedness transit information since June. The latest app version is expanding this feature:
If you need to take transit, Google Maps can help you more easily social distance with live crowdedness information. On Android and iOS globally, you’ll start seeing how crowded your bus, train, or subway line is right now based on real-time feedback from Google Maps users around the world (wherever data is available).Google Maps updates to get you through the holidays
Crowdedness is missing altogether in Apple Maps Japan transit, not surprising as Apple is very slow adding new features and transit only just got around to adding train platform numbers. Google Maps crowdedness information is a welcome feature but be wary about the ‘real-time’ label with the ‘wherever data is available’ sticker.
As the announcement explains, crowdedness data is ‘real-time feedback’. In Japan the feedback is solicited in the app: ‘how crowded is your train’. This is a completely subjective observation and depends on whatever the person making said feedback thinks and feels. Manual feedback may not the only measure, but it is time and train specific beyond the capability of GPS and carries the most weight.
JR East provides crowdedness information collected from train and station cameras that they plug into the JR East app. They also supply this to Google Maps, Yahoo Japan Maps and other map services. Detail level depends on the line: Yamanote line train cameras and sensors provide car by car crowdedness and much more while Chuo line trains sensors only summarize the entire train.
The gap between Google Map feedback and JR East crowdedness data sets can be seen in Google Maps transit directions. JR East supplied data is highlighted in red text labeled ‘live’, Google feedback data is not. In the above screenshot Google Maps feedback lists the Yamanote train as crowded, JR East data does not. The take away: use transit agency data when available, after a few months of using it I find Google Maps feedback crowdedness data is, at best, subjective.