doctor yellow is just one maintenance vehicle. there are hundreds of Automated Obstacle Detection Vehicle that go out from every station, and computer imaging

doctor yellow is just one maintenance vehicle. there are hundreds of Automated Obstacle Detection Vehicle that go out from every station, and computer imaging detects any faults or debris on the tracks. https://international-railway-safety-council.com/wp-content/uploads/2017/09/sasaki-safety-system-for-track-maintenance-vehicle-operation-of-shinkansen.pdf https://international-railway-safety-council.com/wp-content/... I hope we can communicate without downvoting??