uint choices = 0;
        /* Just follow track 1 tile and see if there is a track to follow. (try not to bang in coast or ship) */
        while (tracks != TRACK_BIT_NONE) {
            track = RemoveFirstTrack(&tracks);

            ti = TileIndexDiffCByDiagDir(TrackdirToExitdir(TrackEnterdirToTrackdir(track, diagdir)));
            TileIndex tile_check = TileAddWrap(tile, ti.x, ti.y);
            if (tile_check == INVALID_TILE) continue;

            if (HasVehicleOnPos(tile_check, &scc, FindShipOnTile)) continue;

            TrackBits bits = GetAvailShipTracks(tile_check, TrackdirToExitdir(TrackEnterdirToTrackdir(track, diagdir)));
            if (!IsDiagonalTrack(track)) bits &= TRACK_BIT_CROSS;  // No 90 degree turns.

            if (bits != INVALID_TRACK_BIT && bits != TRACK_BIT_NONE) {
                choices++;
                if (choices < 2 || Chance16(1, 2)) {
                    *track_old = track;
                }
            }