Creating a track
Hover over Draw new:, and select Track from the sub-menu.
Choose the routing mode from the selector at the bottom.
You can select Driving, Walking, Cycling, or as the crow flies.
Driving, Walking and Cycling all use Google's routing algorithms (no matter what map rendering mode you are on), and 'as the crow flies' just draws straight lines.
Using Driving, Walking or Cycling should produce exactly the same route between the places you click as if you went on google maps and got directions between those places with the 'avoid highways' option set.
An entry for the new track should appear in the list of current items at the right
The cursor should also change to a crosshair.
You can now click where you want the track to start. A green dot should appear at this location to mark the start of the track.
Click successive points where you want the track to go through, and a blue line will be drawn through these locations, following roads as per the routing mode selected from the selector in the bottom right.
If it routes a way you don't want to go:
Here, for instance, I've got the routing selector on driving mode.
I don't want to change it permanently to walking mode as I might forget it's on that and continue drawing my track which might then go down footpaths which are unsuitable for cycling.
However, it's routed me down the dual carriageway, as that's the only way in a car. But I know on my bike I can cut through Winthorpe.
To quickly resolve a situation like this:
Right click (anywhwere), and choose Undo Last.
The route will be reverted to how it was before you made the last click that was routed incorrectly.
Then, Right click at the point you next want to go through, hover over Route to here and choose walking mode.
The track now follows the route I want to take (and the routing mode has not changed permanently).