MOT Temporary Traffic Control Plans 2 — Questions and Answers
Question 1: Who is ultimately responsible for approving a Temporary Traffic Control (TTC) plan before work begins on a state highway?
- The prime contractor's safety officer
- The local fire marshal
- The road authority or agency engineer (Correct answer)
- The OSHA compliance officer
Correct answer: The road authority or agency engineer
The road authority or agency engineer holds final approval authority for TTC plans on state highways.
Question 2: In a TTC plan, what does the term 'taper length' refer to?
- The distance vehicles travel before reaching the work zone
- The length of lane shifting or merging transition area (Correct answer)
- The total length of the work zone closure
- The distance between advance warning signs
Correct answer: The length of lane shifting or merging transition area
Taper length is the distance used to transition traffic laterally from one lane path to another in a merge or shift.
Question 3: Which MUTCD formula is used to calculate minimum taper length for speed limits of 45 mph or greater?
- L = W × S² (Correct answer)
- L = W × S / 60
- L = W × S
- L = S² / W
Correct answer: L = W × S²
For speeds 45 mph and above, the MUTCD taper length formula is L = W × S², where W is width in feet and S is speed in mph.
Question 4: A TTC plan includes a note that a particular road section requires 'one-lane, two-way traffic control.' Which device is most appropriate to manage this condition?
- Portable changeable message sign
- Flagger or temporary traffic signal (Correct answer)
- Rumble strips
- Barricade Type III only
Correct answer: Flagger or temporary traffic signal
One-lane, two-way traffic flow is managed by a flagger or a temporary traffic signal to alternate traffic in each direction.
Question 5: When a TTC plan calls for nighttime work, what additional element is typically required that may not be needed during daytime operations?
- Wider buffer spaces between devices
- Increased sign spacing distances
- Lighting or enhanced retroreflective devices (Correct answer)
- Additional law enforcement officers
Correct answer: Lighting or enhanced retroreflective devices
Nighttime work zones require lighting or enhanced retroreflective devices to maintain visibility for drivers and workers.
Question 6: A TTC plan shows a 'buffer space' between the taper and the work area. What is the primary purpose of this buffer?
- To store equipment and materials safely
- To protect workers by providing a clear distance if a vehicle enters the work zone (Correct answer)
- To allow flaggers room to direct traffic
- To separate advance warning signs from the lane closure
Correct answer: To protect workers by providing a clear distance if a vehicle enters the work zone
The buffer space provides a safety cushion between errant vehicles that pass through the taper and the actual work activity area.
Question 7: Which type of TTC plan component marks the downstream end of the work zone and guides traffic back to normal travel lanes?
- Advance warning area devices
- Tangent taper
- Termination area taper (Correct answer)
- Buffer zone channelizing devices
Correct answer: Termination area taper
The termination area taper, also called an end taper, is placed at the downstream end to return traffic to normal alignment.
MOT Temporary Traffic Control Plans 2
Who is ultimately responsible for approving a Temporary Traffic Control (TTC) plan before work begins on a state highway?