Keys
Tab / Shift+Tab next / previous part along the track
WASD move by the step: north / west / south / east, or in View frame forward / left / back / right as the camera looks (arrows pan the map)
F switch the move frame (Compass / View)
E / Q (or PgUp / PgDn, + / −) raise / lower the rail
Shift ×10, Alt ×0.1 with any move
Enter re-centre 2 / 3 view R revert part
Ctrl+Z / Y undo / redo Ctrl+S download G jump to id
B flatten zone around the part (buildings and trees inside it leave the 3D view)
[ / ] shrink / grow it along the track, , / . across
N next zone X remove it