At a standard at-grade junction, the number of severe crossing conflict points becomes 16 when the intersecting roads are:

Introduction / Context:
Traffic conflicts are interactions between vehicles that can lead to crashes. At unchannelized right-angle intersections, the count of crossing, merging, and diverging conflicts depends on the directionality (one-way or two-way) of the approaches.

Given Data / Assumptions:

• Unsignalized, unchannelized at-grade four-leg intersection.
• Geometric approaches have no dedicated turning lanes or medians.
• “Severe” conflicts refer to crossing conflicts.

Concept / Approach:
Two-way movements on both intersecting roads create the maximum permutations of through and turning paths that cross each other, thus maximizing the number of crossing conflict points compared to combinations that include one-way approaches.

Step-by-Step Solution:
Enumerate through and turning movements for each approach in two-way–two-way condition.Count unique crossing paths where two vehicle trajectories intersect at-grade.This standard configuration yields 16 crossing conflict points.

Verification / Alternative check:
Conflict point diagrams in traffic engineering texts show 16 crossing conflicts for two-way–two-way intersections, fewer when any approach is one-way because several opposing movements are eliminated.

Why Other Options Are Wrong:

• Both one-way or mixed one-way/two-way: fewer opposing flows, hence fewer crossing conflicts.
• “None of these”: incorrect because the two-way–two-way case does have 16 crossing conflicts.

Common Pitfalls:

• Confusing total conflicts (crossing + merging + diverging) with crossing only.
• Assuming channelization does not change conflict structure; it does.

Final Answer:
Both two-way roads