Final answer:
Crosswalk lines mark pedestrian crossings, ensuring the safety of individuals by clearly designating where they can safely cross streets.
Step-by-step explanation:
Crosswalk lines are a pair of white or longitudinal lines that mark pedestrian crossings. These are vital for pedestrian safety in cities where individuals follow roads and sidewalks that often require zig-zagged paths to reach their destinations, as seen in the reference figures depicting various paths in a city. Properly marked crosswalks, possibly complemented with traffic signals, enable pedestrians to safely navigate intersections, especially in areas with high foot traffic such as school campuses.