Difficulty: Easy
Correct Answer: 10 cm
Explanation:
Introduction / Context:
Pavement markings communicate lane discipline and passing restrictions. The width of the line affects visibility, retroreflectivity performance, and material consumption, and is standardized for uniformity and driver expectancy.
Given Data / Assumptions:
Concept / Approach:
Most standards specify a nominal line width for longitudinal markings (centre and lane lines) commonly equal to 10 cm for multi-lane highways. Wider markings (e.g., 15 cm) are generally reserved for edge lines or special applications where added conspicuity is desired.
Step-by-Step Solution:
Identify the marking: broken centre line on a four-lane highway.Apply the standard width used for longitudinal lane/centre lines.Select 10 cm as the typical standard thickness (width).
Verification / Alternative check:
Field practice across jurisdictions aligns with 10 cm as the default for lane and centre lines; agency supplements may prescribe different widths for special corridors.
Why Other Options Are Wrong:
12–20 cm are either nonstandard for this specific marking or used for other line types (e.g., wider edge lines, chevrons, or barrier lines).
Common Pitfalls:
Confusing broken centre line with double solid/no-passing markings, which can have different configurations.
Final Answer:
10 cm
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