MUTCD Part 6 Work Zone Standards
Not publishedof exam
Traffic Control Device Placement
Not publishedof exam
Typical Application Diagrams
Not publishedof exam
Work Zone Safety
Not publishedof exam
Signs and Channelizing Devices
Not publishedof exam
Flagging Operations
Not publishedof exam
Traffic Control Theory
Not publishedof exam
Quick Facts
- Exam
- IMSA Work Zone TTC
- Questions
- 100 questions
- Time
- 3 hrs max
- Pass score
- 70
- Weights
- Not published
- Pass rate
- Not published
- Retake
- 1 free, within 1 yr
- Renewal
- 3 yrs, 4 CE hrs
- Source
- MUTCD 11th Ed, Part 6
TTC Zone Order
Warn -> Transition -> Activity -> Termination
Advance warning: inform aheadTransition: redirect the pathActivity: work plus bufferTermination: return to normal
Standard vs Guidance
Standard
- Verb is shall
- Mandatory, rarely deviated
Guidance
- Verb is should
- Recommended, engineering judgment OK
Required vs recommended
TTC Zone Structure
- Advance warning area
- Informs road users ahead
- Transition area
- Redirects normal path
- Activity area
- Work, traffic, buffer space
- Termination area
- Returns to normal path
- Work space
- Closed to road users
- Traffic space
- Routes road users through
- Buffer space
- Recovery room, no storage
Statement Verb Cues
Shall = Standard, should = Guidance, may = Option
Standard: mandatory ruleGuidance: recommended practiceOption: permissive onlySupport: informational, no verb
Option vs Support
Option
- Verb is may
- Permissive, no requirement
Support
- Informational text only
- Never shall, should, or may
Permission vs information
MUTCD Statement Types
- Standard
- Shall; mandatory rule
- Guidance
- Should; recommended practice
- Option
- May; permissive only
- Support
- Informational; no verb
- Standard deviation
- Needs an engineering study
- Guidance deviation
- Needs engineering judgment
Work Duration Categories
- Long-term stationary
- More than 3 days
- Intermediate-term stationary
- 1 day to 3 days
- Short-term stationary
- Over 1 hr, one day
- Short duration
- Up to 1 hour
- Mobile
- Moves continuously or often
- TMP
- TTC, TO, PI plans
Taper Length Fractions
Merge = L, shift = 0.5L, shoulder = 0.33L
Merging taper: full LShifting taper: about halfShoulder taper: about a third
Merging vs Shifting Taper
Merging taper
- Full length L
- Used for lane loss
Shifting taper
- About half L
- Used for lateral shift
Lane loss vs shift
Taper Type Picker
- Merging into one lane→Merging taper(Length = L)
- Lateral shift, no lane loss→Shifting taper(At least 0.5 L)
- Shoulder only, high-speed road→Shoulder taper(At least 0.33 L)
- Speed 40 mph or less→L = WS2/60(Squares the speed)
- Speed 45 mph or more→L = WS(Linear with speed)
- One-lane, two-way section→50-100 ft taper(~20 ft device gaps)
Taper Lengths and Formulas
- Merging taper
- At least L, longest
- Shifting taper
- At least 0.5 L
- Shoulder taper
- At least 0.33 L
- One-lane two-way taper
- 50 to 100 ft
- Downstream taper
- 50 to 100 ft
- L formula, 40 mph
- WS2 / 60
- L formula, 45 mph+
- WS
- S definition
- Posted or operating speed
Speed Split for L
Square below 40 mph, linear above
40 mph or less: WS2/6045 mph or more: WS
Channelizing Device Spacing
- Taper spacing
- 1x speed limit, ft
- Tangent spacing
- 2x speed limit, ft
- One-lane taper devices
- About 20 ft apart
- Downstream taper devices
- About 20 ft apart
Advance Warning Sign Spacing
- Urban low speed
- 100 ft each sign
- Urban high speed
- 350 ft each sign
- Rural roads
- 500 ft each sign
- Expressway freeway
- 1000, 1500, 2640 ft
Buffer and Sight Distance
- Buffer space
- Optional, lateral or longitudinal
- Buffer space rule
- No storage or work
- Longitudinal buffer sizing
- Uses Table 6B-2
- SSD at 30 mph
- 200 ft
- SSD at 55 mph
- 495 ft
- SSD at 65 mph
- 645 ft
Typical Application Index
- TA-10
- Flaggers on two-lane road
- TA-17
- Mobile, two-lane road
- TA-32
- Half closure, high-speed highway
- TA-33
- Stationary closure, divided highway
- TA-35
- Mobile, multi-lane road
- TA-36
- Lane shift on freeway
- TA-37
- Double lane closure, freeway
- Chapter home
- 6P holds all TAs
New Typical Applications
- TA-47
- Bike lane, no detour
- TA-48
- Bike lane, on-road detour
- TA-49
- Shared-use path, diversion
- TA-50
- Detour for shared-use path
- TA-51
- Shoulder closure, bike diversion
- TA-52
- Circular intersection, short-term work
- TA-53
- Circular intersection, flagging
- TA-54
- Circular intersection, lane closure
Class 2 vs Class 3
Class 2
- Baseline for all workers
- Standard, day or night
Class 3
- Night flagger, Guidance level
- More background material
Baseline vs night flagger
Worker Protection
- Positive protection review
- Consider at 45 mph+
- TMA Test Level 2
- 70 km/h rated
- TMA Test Level 3
- 100 km/h rated
- Power line clearance
- 10 ft, up to 50kV
- Power line, 50-200kV
- 15 ft minimum
Pedestrian Access
- Detection plate top
- At least 8 in
- Detection plate bottom
- At most 2 in
- Hand-trailing edge height
- 32 to 38 in
- Alt route width, Option
- 48 in minimum
- Passing space
- 60 in every 200 ft
- Temporary ramp slope
- 12:1 or flatter
Device Height Rule
Low speed is 18 in, fast is 28
Cones: 18 in day, low speedCones: 28 in freeway or night
Taper vs Tangent Spacing
Taper spacing
- 1x the speed limit
- Tighter, more devices
Tangent spacing
- 2x the speed limit
- Wider, fewer devices
Half spacing vs full
Device Spacing Picker
- Devices set in a taper→1x speed limit, ft(Section 6K.01)
- Devices set in a tangent→2x speed limit, ft(Double the taper rule)
- Freeway, high-speed, or night→28 in cones minimum(Section 6K.03)
- Daytime, low-speed roadway→18 in cones minimum(Section 6K.03)
- Need 1-mile legibility→Type C arrow board(96 x 48 in)
- Low-speed urban street→Type A arrow board(48 x 24 in)
Channelizing Devices
- Cone height, day low-speed
- 18 in minimum
- Cone height, freeway night
- 28 in minimum
- Drum height
- 36 in minimum
- Drum width
- 18 in minimum
- Vertical panel height
- 24 in minimum
- Tubular marker height
- 18 in minimum
- Barricade Type 1 or 2
- 24 in min length
- Barricade Type 3
- 48 in min length
Sign Sizes and Mounting
- ROAD WORK sign, roads
- 36 x 36 in
- ROAD WORK sign, freeway
- 48 x 48 in
- ROAD WORK sign, minimum
- 30 x 30 in
- Sign height, rural
- 5 ft minimum
- Sign height, business area
- 7 ft minimum
- Portable sign clearance
- 1 ft minimum
Arrow Boards
- Type A board
- 48 x 24 in
- Type B board
- 60 x 30 in
- Type C board
- 96 x 48 in
- Type C legibility
- 1 mile away
- Dimming requirement
- 50 percent minimum
- Lane-shift rule
- Closures only, never shifts
- Caution mode names
- Flashing or Alternating Diamond
Paddle vs AFAD Sign
Hand paddle
- 18 by 18 in
- Hand-held by flagger
AFAD sign
- 24 by 24 in
- Mounted, remote-controlled
Hand-held vs mechanical
Flagging Method Picker
- One-lane, two-way, short zone→Single flagger(Sees end to end)
- One-lane, two-way, long zone→Flagger at each end(One flagger coordinates)
- Only one approach lane→AFAD device(Trailer or gate-arm type)
- Flagging at night→Class 3 apparel(Guidance, not a Standard)
- Emergency hand-signal only→Red or orange flag(24 in square minimum)
Flagging Tools
- STOP/SLOW paddle
- 18 x 18 in
- Hand signal flag
- 24 in square min
- AFAD STOP/SLOW sign
- 24 x 24 in
- AFAD letter height
- 8 in minimum
- Flashlight use
- Left hand, supplements paddle
Flagger Rules
- Flagger station placement
- Meets stopping sight distance
- Apparel for all workers
- Class 2 or 3
- Night flagger apparel
- Class 3, Guidance level
- Single flagger allowed
- Sees end to end
- Two-flagger control
- One flagger coordinates
Late Merge vs Early Merge
Late merge
- Use all lanes
- Merge at the taper
Early merge
- Merge as soon as possible
- Leave the lane early
Zipper vs traditional merge
Traffic Flow Theory
- Flow (q)
- Vehicles per hour, per lane
- Speed (v)
- Space-mean speed
- Density (k)
- Vehicles per mile, per lane
- Flow equation
- q = v x k
- Bottleneck effect
- Reduces achievable flow
Merge Strategy
- Late merge
- Use all lanes to merge
- Early merge
- Merge as soon as possible
- W9-2a
- Merge Here Take Turns
- R4-9a
- Stay In Lane To Merge Point
- Zipper merge
- Nickname for late merge
Common Traps
Paddle Size vs AFAD Size
Hand paddle: 18 by 18 in ≠ AFAD sign: 24 by 24 in
Standard Verb vs Guidance Verb
Standard always uses shall ≠ Guidance always uses should
Taper Spacing vs Tangent Spacing
Taper devices: 1x speed limit ≠ Tangent devices: 2x speed limit
Arrow Board Closure vs Shift
Arrow boards signal closures only ≠ Never used to signal a shift
Class 2 Apparel vs Class 3
Class 2 covers all workers ≠ Class 3 is for night flaggers
Single Flagger vs Two Flaggers
Single flagger needs full sightline ≠ Two flaggers: one is the coordinator
Buffer Space vs Work Space
Buffer space stays empty, no storage ≠ Work space holds crew and equipment
Last Minute
- 1.Exam = 100 questions, 3 hrs
- 2.Pass = 70; weights = not published
- 3.Merging taper = L (full length)
- 4.Shifting taper = 0.5L; shoulder = 0.33L
- 5.L = WS2/60 at 40 mph
- 6.L = WS at 45 mph+
- 7.Taper spacing = 1x speed limit
- 8.Tangent spacing = 2x speed limit
- 9.Cones = 18in low speed, 28in freeway
- 10.STOP/SLOW paddle = 18 by 18in
- 11.AFAD sign = 24 by 24in
- 12.Arrow boards = closures only, never shifts
- 13.Chapter 6P = 54 typical applications
- 14.Retake = 1 free, within 1 year