Question 5 B is correct answer HTML code is wrong
Question 5 B is correct answer HTML code is wrong
A civil engineer is preparing preliminary design plans for a rural two-lane roadway.
The purpose of the work is to evaluate general alignment feasibility and approximate drainage patterns.
Available information:
County GIS contours with 10-ft interval
Recent LiDAR data with stated vertical accuracy ±1.0 ft
Existing as-built plans from a project completed 15 years ago
No field survey has been performed
Horizontal control is based on an assumed datum
Vertical control references a published benchmark nearby
No right-of-way acquisition or construction staking is included in this phase
Additional information (noise):
Design speed 55 mph
Superelevation will be determined later
Soil report pending
Drainage structures not yet sized
Which statement is most appropriate for this stage of the project?
A. A full control survey is required before any alignment evaluation can be performed.
B. GIS contours and LiDAR data are acceptable for preliminary alignment and drainage evaluation.
C. Existing as-built plans alone provide sufficient accuracy for preliminary design.
D. Construction staking tolerances must be established before proceeding.
No calculations
No surveying theory
One judgment call
Ask yourself: early vs final
Reply with A, B, C, or D.
After you answer, I’ll tell you:
why the correct choice is correct
which word in the question kills the other options
how this exact question style steals points on the real exam
B
✅ Correct — B.
Here’s the exam-clean reasoning, very short:
This is preliminary design (alignment feasibility + approximate drainage)
Early stage ⇒ approximate data is acceptable
GIS contours + LiDAR with stated accuracy are appropriate
No construction or staking yet ⇒ no control survey required now
Why the others are wrong (one-liners):
A: Full control survey is for final design / construction, not preliminary
C: Old as-builts alone are unreliable
D: Staking tolerances are irrelevant at this stage
Rule to remember:
Early planning → GIS/LiDAR OK
Final design / construction → field survey required
You handled this exactly right.
A survey crew measures the distance between two control points five times.
The true distance is 100.00 ft.
Measured values:
100.42 ft
100.41 ft
100.43 ft
100.42 ft
100.41 ft
Which statement best describes these measurements?
A. Accurate and precise
B. Accurate but not precise
C. Precise but not accurate
D. Neither accurate nor precise
Take 5–10 seconds.
Don’t overthink.
A civil engineer is preparing preliminary grading plans for a private development.
No nearby published benchmarks are available.
The plans note:
“All elevations are based on an assumed datum.”
No tie to NAVD88 is shown.
The project is not intended for construction staking.
Which statement is correct?
A. An assumed datum is unacceptable for any grading work.
B. An assumed datum is acceptable for preliminary design.
C. A published vertical datum must always be used.
D. Elevations without NAVD88 are invalid.
A county GIS database is used to identify drainage flow paths for a feasibility study.
The GIS contours are derived from LiDAR with ±1 ft vertical accuracy.
What is the primary limitation of using GIS data for this purpose?
A. GIS data cannot represent elevations.
B. GIS data lacks sufficient vertical accuracy for final design.
C. GIS data cannot be used for preliminary studies.
D. GIS data must always be field-verified before any use.
Do not bring real-world engineering standards into it
Answer how the exam thinks
One letter per question (e.g., 1:C, 2:B, 3:B)
After you answer, I’ll:
confirm
explain the trap logic
give you a one-sentence rule for each topic so this section stops being “marginal” permanently
1 c2 b
Good — and you were right on both. Let’s lock them in and finish the set.
1: C ✅
2: B ✅
Now I’ll confirm why, very exam-focused, then we’ll do Trap 3.
Measurements are tightly clustered (100.41–100.43) but far from the true value (100.00).
Tight cluster → precise
Far from true → not accurate
✅ Answer: C — Precise but not accurate
One-line rule:
Precision = repeatability; Accuracy = closeness to truth.
Key phrases:
preliminary grading
private development
not for construction staking
Assumed datum is acceptable here.
✅ Answer: B — An assumed datum is acceptable for preliminary design
One-line rule:
Assumed datums are acceptable for preliminary work; published datums are required for construction/final work.
You didn’t answer this one yet — here it is again:
A county GIS database is used to identify drainage flow paths for a feasibility study.
The GIS contours are derived from LiDAR with ±1 ft vertical accuracy.
What is the primary limitation?
A. GIS data cannot represent elevations.
B. GIS data lacks sufficient vertical accuracy for final design.
C. GIS data cannot be used for preliminary studies.
D. GIS data must always be field-verified before any use.
👉 Correct answer: B ✅
Why:
GIS/LiDAR is fine for feasibility and planning
±1 ft is not adequate for final design
A roadway centerline includes a simple circular curve connecting two tangents.
The following information is shown on the plans:
PI station = 32+50
Back tangent bearing = S 62° E
Forward tangent bearing = N 44° E
Radius of curve = 600 ft
Central angle = 74°
Tangent length shown on plans = 398.7 ft
Curve length shown = 774.9 ft
Superelevation = 6%
Design speed = 50 mph
Datum assumed
Vertical curve PVI at Sta. 33+10
Cross slope changes north of Sta. 34+00
Drainage structure at Sta. 31+90
Additional note:
Stationing increases from south to north.
At Sta. 31+80, is the centerline located on the:
A. Back tangent
B. Curve
C. Forward tangent
D. Cannot be determined from given information