Complete the track from A to B so that the rows and columns contain the same number of track segments as are indicated in the clues to the top and right of the grid. There are only straight and 90-degree curved rail sections, and the track may not cross itself.
On a touch screen, a tap does what a click does, and a long press what a right-click does (more ways to right-click).
A click near the middle of a square addresses the square, and a click near one of its sides addresses the edge there.
Click a square or edge to lay track there: on an edge, a segment joining the two squares; in a square, the purple bed that says it holds track, even before you know which edges it crosses. Click it again to take the track away. Right-click it to mark it as holding no track (a cross in a square or on an edge), or take the mark away again. Drag from a square that already holds track, through the squares beside it, to lay a segment across every edge you cross, or, when the first edge has one, to take them away.
With the keyboard, the arrow keys move a cursor around the board. Enter does what a click does to the square or edge under it, and Space what a right-click does.
A left-drag from a square that holds no track yet, and any right-drag, marks squares instead: drag along a row or column to lay a straight line of is-track or is-not-track indicators, useful for filling in rows or columns to match the clue. So mark the squares first, then drag through them to lay the track. Either kind of drag is one step of Undo.
A right-click crosses an edge only when it lands on the narrow strip right along that edge; anywhere else in a square it marks the square, which is the mark you will want far more often.
A square that holds track is purple, whether or not its rails are in yet, and so is a square a rail leads into. A square you have said holds no track shows a cross, the same “ruled out” mark the other puzzles use, and an edge the track can’t cross shows a smaller one.
Hint explains the next step rather than simply making it, and because Tracks decides two different kinds of thing — whole squares, and the individual sides between them — the mark tells you which one it means.
Half of most Tracks deductions is a clue rather than anything on the grid, so when a hint says “this column already has all 4 of the track squares its clue allows”, the 4 it means is the one that has changed color, and the squares it is counting are the ones outlined.
Every hint is a deduction you could have made from what is on the board, so it never guesses. It is refused while anything you have marked contradicts the solution; the offending squares are marked in red instead, exactly as they are for Check & save.
These parameters are available from the ‘Custom type…’ option on the ‘Type’ menu.