FE Civil Transportation Engineering
Practice Exam 2026–2027 | Full-Length
Questions, Answers & Detailed
Rationales
1. A two-lane rural highway has a design speed of 70 mi/h. For a horizontal
curve with a superelevation rate of 0.08 and a side-friction factor of 0.10,
what is the approximate minimum radius of the curve?
A. 1,250 ft
B. 1,470 ft
C. 1,680 ft
D. 1,920 ft
Answer: 1,470 ft
Rationale: The approximate relationship is R = V²/[15(e + f)]. Substituting V = 70
mi/h, e = 0.08, and f = 0.10 gives R = 4900/*15(0.18)+ ≈ 1,815 ft. Depending on
the applicable design table and rounding convention, a larger practical radius
may be selected; the governing design value should be verified against the
specified standard.
, 2. A vehicle travels at 55 mi/h on a roadway with a 3% downgrade. Which
factor most directly affects the minimum stopping sight distance?
A. Pavement thickness
B. Grade
C. Lane width
D. Median width
Answer: Grade
Rationale: Grade changes the gravitational component of vehicle deceleration.
A downgrade increases stopping distance because gravity acts in the direction of
vehicle travel.
3. For a crest vertical curve, the controlling design consideration is generally:
A. Pavement drainage
B. Headlight illumination
C. Stopping sight distance
D. Superelevation runoff
Answer: Stopping sight distance
Rationale: Crest curves restrict the driver's line of sight over the crest. Therefore,
stopping sight distance commonly controls the required curve length.
4. A sag vertical curve is being designed for nighttime operation. Which
criterion may control the minimum length?
A. Driver reaction time only
B. Headlight sight distance
C. Pavement friction only
D. Shoulder width
Answer: Headlight sight distance
,Rationale: On sag curves, the roadway surface ahead may be hidden by the
geometry of the depression. At night, headlight sight distance can govern the
curve length.
5. A roadway has a 6% grade and a 2% cross slope. What is the primary
concern with increasing the longitudinal grade on a high-speed facility?
A. Reduced vehicle acceleration and increased drainage problems
B. Increased stopping distance and reduced heavy-vehicle performance
C. Reduced pavement temperature
D. Increased lane capacity
Answer: Increased stopping distance and reduced heavy-vehicle performance
Rationale: Steep grades affect both braking requirements and heavy-vehicle
operating speeds. Long steep upgrades can produce substantial speed
differentials between passenger cars and trucks.
6. In traffic-flow theory, the fundamental relationship among flow q, density
k, and space-mean speed u is:
A. q = k/u
B. q = u/k
C. q = ku
D. q = k + u
Answer: q = ku
Rationale: Traffic flow is the product of density and space-mean speed. When
density is expressed in vehicles per mile and speed in miles per hour, flow is
obtained in vehicles per hour.
7. A traffic stream has a density of 30 veh/mi/lane and a space-mean speed of
45 mi/h. What is the flow?
A. 675 veh/h/lane
B. 1,050 veh/h/lane
, C. 1,350 veh/h/lane
D. 1,500 veh/h/lane
Answer: 1,350 veh/h/lane
Rationale: Using q = ku, q = (30)(45) = 1,350 veh/h/lane.
8. Under the Greenshields linear speed-density model, the speed-density
relationship is:
A. Exponential
B. Linear
C. Logarithmic
D. Constant
Answer: Linear
Rationale: The Greenshields model assumes speed decreases linearly with
increasing traffic density. This simplified model is frequently used to derive
relationships among speed, flow, and density.
9. If the jam density of a roadway is 180 veh/mi/lane and the free-flow speed
is 60 mi/h, the Greenshields model predicts the maximum flow at
approximately what density?
A. 30 veh/mi/lane
B. 45 veh/mi/lane
C. 90 veh/mi/lane
D. 180 veh/mi/lane
Answer: 90 veh/mi/lane
Rationale: For the Greenshields model, maximum flow occurs at one-half the
jam density. Thus k at capacity = 180/2 = 90 veh/mi/lane.
10.Using the same roadway in Question 9, what is the speed at maximum
flow?
Practice Exam 2026–2027 | Full-Length
Questions, Answers & Detailed
Rationales
1. A two-lane rural highway has a design speed of 70 mi/h. For a horizontal
curve with a superelevation rate of 0.08 and a side-friction factor of 0.10,
what is the approximate minimum radius of the curve?
A. 1,250 ft
B. 1,470 ft
C. 1,680 ft
D. 1,920 ft
Answer: 1,470 ft
Rationale: The approximate relationship is R = V²/[15(e + f)]. Substituting V = 70
mi/h, e = 0.08, and f = 0.10 gives R = 4900/*15(0.18)+ ≈ 1,815 ft. Depending on
the applicable design table and rounding convention, a larger practical radius
may be selected; the governing design value should be verified against the
specified standard.
, 2. A vehicle travels at 55 mi/h on a roadway with a 3% downgrade. Which
factor most directly affects the minimum stopping sight distance?
A. Pavement thickness
B. Grade
C. Lane width
D. Median width
Answer: Grade
Rationale: Grade changes the gravitational component of vehicle deceleration.
A downgrade increases stopping distance because gravity acts in the direction of
vehicle travel.
3. For a crest vertical curve, the controlling design consideration is generally:
A. Pavement drainage
B. Headlight illumination
C. Stopping sight distance
D. Superelevation runoff
Answer: Stopping sight distance
Rationale: Crest curves restrict the driver's line of sight over the crest. Therefore,
stopping sight distance commonly controls the required curve length.
4. A sag vertical curve is being designed for nighttime operation. Which
criterion may control the minimum length?
A. Driver reaction time only
B. Headlight sight distance
C. Pavement friction only
D. Shoulder width
Answer: Headlight sight distance
,Rationale: On sag curves, the roadway surface ahead may be hidden by the
geometry of the depression. At night, headlight sight distance can govern the
curve length.
5. A roadway has a 6% grade and a 2% cross slope. What is the primary
concern with increasing the longitudinal grade on a high-speed facility?
A. Reduced vehicle acceleration and increased drainage problems
B. Increased stopping distance and reduced heavy-vehicle performance
C. Reduced pavement temperature
D. Increased lane capacity
Answer: Increased stopping distance and reduced heavy-vehicle performance
Rationale: Steep grades affect both braking requirements and heavy-vehicle
operating speeds. Long steep upgrades can produce substantial speed
differentials between passenger cars and trucks.
6. In traffic-flow theory, the fundamental relationship among flow q, density
k, and space-mean speed u is:
A. q = k/u
B. q = u/k
C. q = ku
D. q = k + u
Answer: q = ku
Rationale: Traffic flow is the product of density and space-mean speed. When
density is expressed in vehicles per mile and speed in miles per hour, flow is
obtained in vehicles per hour.
7. A traffic stream has a density of 30 veh/mi/lane and a space-mean speed of
45 mi/h. What is the flow?
A. 675 veh/h/lane
B. 1,050 veh/h/lane
, C. 1,350 veh/h/lane
D. 1,500 veh/h/lane
Answer: 1,350 veh/h/lane
Rationale: Using q = ku, q = (30)(45) = 1,350 veh/h/lane.
8. Under the Greenshields linear speed-density model, the speed-density
relationship is:
A. Exponential
B. Linear
C. Logarithmic
D. Constant
Answer: Linear
Rationale: The Greenshields model assumes speed decreases linearly with
increasing traffic density. This simplified model is frequently used to derive
relationships among speed, flow, and density.
9. If the jam density of a roadway is 180 veh/mi/lane and the free-flow speed
is 60 mi/h, the Greenshields model predicts the maximum flow at
approximately what density?
A. 30 veh/mi/lane
B. 45 veh/mi/lane
C. 90 veh/mi/lane
D. 180 veh/mi/lane
Answer: 90 veh/mi/lane
Rationale: For the Greenshields model, maximum flow occurs at one-half the
jam density. Thus k at capacity = 180/2 = 90 veh/mi/lane.
10.Using the same roadway in Question 9, what is the speed at maximum
flow?
