Level 139 solution

Solver-verified route

1. Place Piece 1 across column 5 row 3, column 5 row 4, column 5 row 5, column 6 row 5.
2. Place Piece 2 across column 1 row 3, column 2 row 3.
3. Place Piece 3 across column 4 row 2, column 5 row 2, column 6 row 2, column 7 row 2.
4. Place Piece 4 at column 6, row 3.
5. Place Piece 5 at column 7, row 3.

Part of the "Four lanes" chapter. The solver certified 240 solving lines with 93% of in-between placements being dead ends, for a difficulty score of 18.5 (grade 4 of 5).