Normal sudoku rules apply. Draw a single road that travels orthogonally from cell to cell, never branching, crossing, or overlapping, and which eventually closes into a loop. The road must pass through every house. Borders marked with traffic lights are controlled intersections that the road cannot cross. The bold 3×3 borders divide the road into segments. Within each segment, all digits must be pairwise prime (that is, any two digits in the same segment share no common factor greater than 1). A digit in a house equals the length of the segment containing it, while a digit in a speed camera counts how many road cells appear in the ENTIRE row of that camera, including the camera cell itself. Note: A segment does not necessarily contain a house. Any segment of length 1 must contain the digit 1.