Ctrl-click a free connection point: add a tower there, connected.
Ctrl-drag from one: a line of towers to where you let go, or up to another part's free point.
Right-click a part: change its type, or remove it from its line.
Right-click a connection: add a tower there, or fill it with towers.
(Cmd or Alt work like Ctrl; Esc cancels.)
No map data loaded.
With Snap to Streets on, a part dropped within 30 m of a street lands on its centre line and a Ctrl-dragged tower line follows the streets. Hold Shift, or drop farther away, to leave the street.
Red: buildings under the guideway. Orange: guideway more than 20 m from any street.
Not checked.
Check marks the parts in error (red rings). Align... shows where parts would go (blue arrows, new towers green) and waits for Apply, one undo step. It does not know streets: load the map data to see what an alignment moves off them.