What is the minimum lateral clearance specified for road markers from the edge of a kerb so that the markers do not obstruct vehicles and remain visible?

Introduction / Context:
Road markers (such as delineators or boundary markers) placed along kerbed edges must maintain a safe lateral offset to avoid being struck by passing vehicles and to remain within drivers’ sight envelopes. Standards prescribe minimum clearances that balance safety, visibility, and practical placement in constrained rights-of-way.

Given Data / Assumptions:

• Markers are along a kerbed roadway edge.
• Lateral clearance is measured horizontally from the kerb edge to the marker.
• Urban context with typical lane widths and shy-line considerations.

Concept / Approach:
A minimum offset prevents mirror and body strikes and accommodates shy distances near vertical objects. A commonly cited minimum offset for such markers is about 50 cm from the kerb face, adequate for most light vehicles while remaining readable and within maintenance reach.

Step-by-Step Solution:
Identify the kerb face as reference.Apply standard minimum offset: ≥ 0.50 m.Locate and anchor markers accordingly, ensuring uniformity.

Verification / Alternative check:
Practical urban roadway sections frequently adopt 0.5 m as a workable minimum; larger offsets may be used on high-speed roads for additional shy distance.

Why Other Options Are Wrong:

• 40–45 cm: insufficient shy distance; higher risk of strikes.
• 55–60 cm: acceptable but not the minimum; consumes more verge width.

Common Pitfalls:

• Measuring from the carriageway edge line rather than from the kerb face.
• Ignoring local constraints like drains and utility covers which may require local adjustments.

Final Answer:
50 cm