Which sequence correctly describes the stages of highway route selection and field investigations from initial study to final design geometry?
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ADuring reconnaissance, the general route of the alignment is selected
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BAfter reconnaissance, a trace is cut along the selected alignment
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CThe last stage is the detailed surveys to establish the required highway geometry
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DAll of the above
Answer
Correct Answer: All of the above
Explanation
Introduction / Context:Highway location proceeds through progressively detailed stages. Early studies identify feasible corridors; subsequent field work refines these into surveyed alignments with precise horizontal and vertical geometry for design and construction.
Given Data / Assumptions:
- Standard sequence: reconnaissance → preliminary location/trace cutting → detailed surveys and design.
- Terrain and constraints are evaluated at each step.
Concept / Approach:Reconnaissance screens alternatives and selects a general route using maps, satellite imagery, and brief field visits. Trace cutting physically marks the centerline on ground to assess practicality and local obstacles. Detailed surveys (plan and profile, cross-sections, benchmarks) then deliver the data needed to finalize curves, grades, and earthworks.
Step-by-Step Solution:Stage 1: Reconnaissance → choose general alignment corridor.Stage 2: Trace cutting → mark and walk the line; adjust locally as needed.Stage 3: Detailed surveys → fix geometries, staking, and control for design.
Verification / Alternative check:This sequence is standard in transportation engineering textbooks and aligns with agency procedures worldwide.
Why Other Options Are Wrong:
- A–C are each correct but incomplete when taken alone; only D captures the full, ordered process.
Common Pitfalls:Skipping control establishment and benchmarks before detailed profiles; making large alignment changes after detailed surveys, which increases cost and time.
Final Answer:All of the above