Traffic engineering application: a collision (accident) diagram is prepared primarily to analyze patterns and to select countermeasures. Which statements are correct uses?

Introduction / Context:
Collision diagrams are location-specific charts that plot accident details (type, severity, direction, time) at an intersection or along a road segment. They help traffic engineers identify hazardous patterns and design targeted treatments such as signal timing changes, geometric modifications, or signage improvements.

Given Data / Assumptions:

• Statements: (1) study accident pattern; (2) eliminate accidents; (3) determine remedial measures; (4) make statistical analysis of accidents.
• Purpose is analytical/diagnostic, not a guarantee of elimination.

Concept / Approach:
Collision diagrams reveal recurring crash types and contributing factors (e.g., right-angle collisions, rear-ends), guiding the choice of countermeasures. While they inform statistical summaries, they are not themselves general statistical tools; broader crash databases serve that role. Importantly, diagrams aid in reducing risk but cannot “eliminate” accidents outright.

Step-by-Step Solution:
Confirm (1): Yes—primary use is to study patterns.Confirm (3): Yes—used to select/justify remedial measures.Evaluate (2): Overstated; no method guarantees elimination.Evaluate (4): While analysis may follow, the diagram itself is not the general statistical tool; it supports targeted analysis rather than full statistical treatment.Therefore, 1 and 3 are correct.

Verification / Alternative check:
Guidelines in traffic safety manuals describe collision diagrams as diagnostic aids to propose engineering, enforcement, or education measures.

Why Other Options Are Wrong:

• (a) Includes elimination claim—unrealistic.
• (c) Omits the essential pattern-study role (1).
• (d) Retains elimination and overemphasizes statistics as a primary purpose.

Common Pitfalls:
Assuming any single tool can fully eliminate accidents; confusing supporting visuals with comprehensive statistical methods.

Final Answer:
1 and 3 are correct (study accident pattern; determine remedial measures)