Road markings – standard thickness (width) of broken lane lines On multi-lane roads, what is the usual width of the broken white line used to separate lanes?

Introduction / Context:
Lane line width affects visibility, driver guidance, and material consumption. Standards specify consistent dimensions for broken (segmented) lane markings on multi-lane facilities.

Given Data / Assumptions:

• Standard multi-lane road marking practice.
• Broken white lines delineating lanes.

Concept / Approach:
Typical specifications adopt a nominal width of about 10 cm for lane lines, balancing conspicuity with economy. Length of segments and gaps are standardized separately.

Step-by-Step Solution:
Identify the standard nominal lane line width.Select 10 cm as the usual value.

Verification / Alternative check:
Field practice and drawings corroborate 100 mm as the default lane line width for most highway classes.

Why Other Options Are Wrong:
Wider widths (12–20 cm) are used for edge lines, special locations, or high-visibility needs; they are not the default for lane separation.

Common Pitfalls:
Confusing edge line width with lane line width; assuming urban arterials always use wider lines.

Final Answer:
10 cm