Traffic volume study at intersections At a road intersection, traffic volume studies are carried out to determine counts of which movement categories?

Introduction / Context:
Intersection analysis requires knowledge of turning movement counts (TMCs). These disaggregate total flow into approach-based through, left-turn, and right-turn movements that drive capacity, signal timing, and geometric design.

Given Data / Assumptions:

• Study location is a typical at-grade intersection.
• Counting intervals commonly 5–15 minutes for peak-hour analysis.
• Movements classified by leg and by turn (left, through, right).

Concept / Approach:
Design of lanes, channelization, storage lengths, and phasing requires the distribution of movements. Thus, all three categories—through, left-turn, and right-turn—must be recorded separately for each approach.

Step-by-Step Solution:

Verification / Alternative check:
Standard TMC templates and traffic software require exactly these inputs for analysis per HCM/IRC methods.

Why Other Options Are Wrong:
Any single movement alone is insufficient for design; complete movement counts are needed.

Common Pitfalls:
Not separating heavy vehicles; inconsistent intervals; ignoring pedestrian and cyclist flows when relevant.

Final Answer:
all the above.