ATSSA Traffic Control Supervisor Re-certification ACTUAL
EXAM WITH LATEST VERSION 2026-2027 QUESTION AND
ANSWERS RATED A GRADE.
What is the formula for minimum taper length for speeds of 40 MPH or less?
A. L = (WS²)/60
B. L = WS
C. L = (WS²)/40
D. L = 2WS
Correct Answer: A. L = (WS²)/60
Rationale
For speeds of 40 MPH or less, the minimum taper length is calculated using the
formula L = (WS²)/60, where W is the lane width and S is the speed. For speeds of
45 MPH or more, the formula is L = WS. This ensures adequate transition distance
for vehicles.
DIF: Cognitive Level: Understand (Comprehension)
TOP: Nursing Process: Planning
MSC: NCLEX: Safe and Effective Care Environment
The off-peak 85th percentile speed is the speed at or below which 85% of
vehicles travel operating speed in free-flow conditions. This speed should be
used in formulas for:
A. Minimum taper length
B. Barrier selection
C. Device spacing
D. Advanced warning sign spacing
Correct Answer: A. Minimum taper length.
Rationale
The 85th percentile speed is used in formulas for minimum taper length. It
,represents the speed at which most vehicles travel and is the standard for
designing traffic control devices.
DIF: Cognitive Level: Understand (Comprehension)
TOP: Nursing Process: Planning
MSC: NCLEX: Safe and Effective Care Environment
What is the distance of L for 25 MPH with a 12-foot lane width?
A. 125 feet
B. 245 feet
C. 540 feet
D. 660 feet
Correct Answer: A. 125 feet.
Rationale
Using the formula L = (WS²)/60 for speeds 40 MPH or less: L = (12 × 25²)/60 = (12
× 625)/60 = 7,500/60 = 125 feet. This provides the minimum taper length required
for a 25 MPH speed zone.
DIF: Cognitive Level: Apply (Application)
TOP: Nursing Process: Planning
MSC: NCLEX: Safe and Effective Care Environment
What is the distance of L for 35 MPH with a 12-foot lane width?
A. 125 feet
B. 245 feet
C. 540 feet
D. 660 feet
Correct Answer: B. 245 feet.
Rationale
Using the formula L = (WS²)/60 for speeds 40 MPH or less: L = (12 × 35²)/60 = (12
, × 1,225)/60 = 14,700/60 = 245 feet. This provides the minimum taper length
required for a 35 MPH speed zone.
DIF: Cognitive Level: Apply (Application)
TOP: Nursing Process: Planning
MSC: NCLEX: Safe and Effective Care Environment
What is the distance of L for 45 MPH with a 12-foot lane width?
A. 125 feet
B. 245 feet
C. 540 feet
D. 660 feet
Correct Answer: C. 540 feet.
Rationale
For speeds of 45 MPH or more, the formula L = WS is used: L = 12 × 45 = 540 feet.
This provides the minimum taper length required for a 45 MPH speed zone.
DIF: Cognitive Level: Apply (Application)
TOP: Nursing Process: Planning
MSC: NCLEX: Safe and Effective Care Environment
What is the distance of L for 55 MPH with a 12-foot lane width?
A. 245 feet
B. 540 feet
C. 660 feet
D. 780 feet
Correct Answer: C. 660 feet.
Rationale
For speeds of 45 MPH or more, the formula L = WS is used: L = 12 × 55 = 660 feet.
This provides the minimum taper length required for a 55 MPH speed zone.
EXAM WITH LATEST VERSION 2026-2027 QUESTION AND
ANSWERS RATED A GRADE.
What is the formula for minimum taper length for speeds of 40 MPH or less?
A. L = (WS²)/60
B. L = WS
C. L = (WS²)/40
D. L = 2WS
Correct Answer: A. L = (WS²)/60
Rationale
For speeds of 40 MPH or less, the minimum taper length is calculated using the
formula L = (WS²)/60, where W is the lane width and S is the speed. For speeds of
45 MPH or more, the formula is L = WS. This ensures adequate transition distance
for vehicles.
DIF: Cognitive Level: Understand (Comprehension)
TOP: Nursing Process: Planning
MSC: NCLEX: Safe and Effective Care Environment
The off-peak 85th percentile speed is the speed at or below which 85% of
vehicles travel operating speed in free-flow conditions. This speed should be
used in formulas for:
A. Minimum taper length
B. Barrier selection
C. Device spacing
D. Advanced warning sign spacing
Correct Answer: A. Minimum taper length.
Rationale
The 85th percentile speed is used in formulas for minimum taper length. It
,represents the speed at which most vehicles travel and is the standard for
designing traffic control devices.
DIF: Cognitive Level: Understand (Comprehension)
TOP: Nursing Process: Planning
MSC: NCLEX: Safe and Effective Care Environment
What is the distance of L for 25 MPH with a 12-foot lane width?
A. 125 feet
B. 245 feet
C. 540 feet
D. 660 feet
Correct Answer: A. 125 feet.
Rationale
Using the formula L = (WS²)/60 for speeds 40 MPH or less: L = (12 × 25²)/60 = (12
× 625)/60 = 7,500/60 = 125 feet. This provides the minimum taper length required
for a 25 MPH speed zone.
DIF: Cognitive Level: Apply (Application)
TOP: Nursing Process: Planning
MSC: NCLEX: Safe and Effective Care Environment
What is the distance of L for 35 MPH with a 12-foot lane width?
A. 125 feet
B. 245 feet
C. 540 feet
D. 660 feet
Correct Answer: B. 245 feet.
Rationale
Using the formula L = (WS²)/60 for speeds 40 MPH or less: L = (12 × 35²)/60 = (12
, × 1,225)/60 = 14,700/60 = 245 feet. This provides the minimum taper length
required for a 35 MPH speed zone.
DIF: Cognitive Level: Apply (Application)
TOP: Nursing Process: Planning
MSC: NCLEX: Safe and Effective Care Environment
What is the distance of L for 45 MPH with a 12-foot lane width?
A. 125 feet
B. 245 feet
C. 540 feet
D. 660 feet
Correct Answer: C. 540 feet.
Rationale
For speeds of 45 MPH or more, the formula L = WS is used: L = 12 × 45 = 540 feet.
This provides the minimum taper length required for a 45 MPH speed zone.
DIF: Cognitive Level: Apply (Application)
TOP: Nursing Process: Planning
MSC: NCLEX: Safe and Effective Care Environment
What is the distance of L for 55 MPH with a 12-foot lane width?
A. 245 feet
B. 540 feet
C. 660 feet
D. 780 feet
Correct Answer: C. 660 feet.
Rationale
For speeds of 45 MPH or more, the formula L = WS is used: L = 12 × 55 = 660 feet.
This provides the minimum taper length required for a 55 MPH speed zone.
