Module 1: Work Zone Traffic Control

1
Module 1 Work Zone Traffic Control
2
Overview of Module 1

• Underlying principles of work zone traffic
  control
• Manual of Uniform Traffic Control Device (MUTCD)
• Features of work zone traffic control
• Hazards associated with work zone traffic control
• Injury prevention techniques
• Summary

3
Work Zone Traffic Control

• Influences drivers perception of risk
• Provides information on potential hazards
• Minimizes aggressive behavior
• Assists in navigation
• Engineering concerns for work zones
• Primary focus Safe and efficient movement of
  vehicles through work zone
• Relatively less emphasis on safety of
  construction workers

4
Type of Barrier

• Rigid Barriers
• Provide separation between
• Opposing traffic lanes
• Traffic lanes and work area
• Cause damage to motorists if struck

Concrete barrier separating traffic lanes and
work area
Concrete barrier separating opposing traffic
5
Type of Barrier

• Flexible barriers (channelizing devices)
• Provide nominal protection for workers
• Flexible and deformable, do not cause damage if
  struck

Concrete barriers to separate work area
Flexible barrier separating traffic lanes and
work area
Channelizing devices for delineation
6
Sample Road Projects and Potential Hazards
Vehicles parked within work area
Passing traffic in close proximity to the
on-foot worker with minimal protection from
flexible barrier
Flashing arrow board is not operating
7
Components of Temporary Traffic Control Zones
(Source MUTCD 2003)

• Advanced Warning Area
• Transition Area
• Activity Area
• Work space
• Traffic space
• Buffer space
• Termination Area

8
Worker Safety Considerations in Work Zone Traffic
Control

• Modifying traffic control strategies to influence
  drivers perception of risk
• Leads to more careful and slower driving
• Improves safety for the workers
• Examples
• Providing active warning devices
• Illuminated arrow boards
• Reliable advisory speed limit
• Active message with flashers
• Narrower lane widths
• Longer and/or wider buffer zones
• Rigid barriers to separate workers from travel
  lanes

9
Positive Guidance Approach

• May be used to improve safety in work zones
• Combines highway/traffic engineering features
  with what rational drivers expect
• Considers
• Various age groups of drivers
• Complexity of work zone information handling
• Limited capability of humans for detecting,
  processing, and remembering information

10
MUTCD Manual on Uniform Traffic Control
Devices

• Recognized as the national standard
• Enforcement agencies often adopt it by reference
• Provides guidance, options and supporting
  materials
• To assist professionals in making decisions
  regarding the use of traffic control on streets
  and highways

11
MUTCD- Part 6 Temporary Traffic Control

• Primary function of
• temporary traffic control
• To provide for reasonably safe and efficient
  movement of road users through or around
  temporary traffic control zones while reasonably
  protecting workers, responders to traffic
  incidents, and equipment

12
Temporary Traffic Control

• Work zones present constantly changing conditions
• Unexpected by the road user
• Creates higher degree of vulnerability for workers

13
Temporary Traffic Control Devices

• Temporary traffic control (TTC) devices include
• Signs
• Signals
• Markings
• Other devices
• Used to regulate, warn, or guide road users

14
Types of TTC Applications

• Each TTC zone is different
• Many variables affect the needs of each zone
• Location of work
• Duration of work
• Highway type
• Geometrics
• Vertical and horizontal alignment, intersections,
  interchanges, etc.
• Road user volumes
• Road vehicle mix (buses, trucks, and cars) and
  road user speeds

15
Work Duration

• Major factor in determining the number and types
  of devices used in TTC zones
• As per the MUTCD, five categories of work
  duration are defined
• Long-term stationary is work that occupies a
  location more than 3 days
• Intermediate-term stationary is work that
  occupies a location more than one daylight period
  up to 3 days, or nighttime work lasting more than
  1 hour
• Short-term stationary is daytime work that
  occupies a location for more than 1 hour within a
  single daylight period
• Short duration is work that occupies a location
  up to 1 hour
• Mobile is work that moves intermittently or
  continuously.

16
Long Term Stationary Work(more than 3 days)

• Typically utilize a full range of TTC procedures
  and devices
• Project duration far exceeds installation time of
  TTC
• TTC elements may include
• Larger channelizing devices, temporary roadways,
  and temporary traffic barriers
• Retroreflective and/or illuminated devices

17
Intermediate-Term Stationary Work (up to 3 days,
or nighttime work lasting more than 1 hour)

• May not be practical to use the same procedures
  or devices for long-term stationary TTC zones
• Such as altered pavement markings, temporary
  traffic barriers, and temporary roadways
• Increased time to place and remove these devices
  could significantly lengthen the project, thus
  increasing exposure time

18
Short-Term Stationary Work (more than 1 hour
within a single daylight period)

• Most maintenance and utility operations are
  short-term stationary work
• Include activities that might involve different
  treatments
• Devices having greater mobility might be
  necessary
• Signs mounted on trucks
• Appropriately colored or marked vehicles with
  rotating/strobe lights may be used in place of
  signs and channelizing devices
• May be augmented with signs or arrow panels

19
Short Duration Work(up to 1 hour)

• Often takes longer to set up and remove the TTC
  zone than to perform the work
• Workers face hazards in setting up and taking
  down the TTC zone
• Delays affecting road users are significantly
  increased when additional devices are installed
  and removed
• Simplified control procedures may be warranted
  for short-duration work
• Reduction in the number of devices
• Use of high-intensity rotating, flashing,
  oscillating, or strobe lights on work vehicles

20
Mobile Work

• Often involve frequent short stops for activities
  
• Such as litter cleanup, pothole patching, or
  utility operations, and are similar to
  short-duration operations
• TTC zones may includes
• Warning signs, high-intensity rotating, flashing,
  oscillating, or strobe lights on a vehicle,
  flags, and/or channelizing devices
• Flaggers
• A shadow vehicle equipped with an arrow panel or
  a sign following the work vehicle
• Appropriately colored and marked vehicles with
  signs, flags, high-intensity rotating, flashing,
  oscillating, or strobe lights, truck-mounted
  attenuators, and arrow panels or portable
  changeable message signs may follow a train of
  moving work vehicles

21
Worker Safety Considerations

• Key elements that SHOULD be considered to improve
  worker safety
• Training
• Worker safety apparel
• Temporary traffic barriers
• Speed reduction measures
• Planning of activity area
• Planning for worker safety

Worker safety apparel
22
Worker Safety Consideration - TRAINING

• All workers should be trained on
• Working safely adjacent to vehicular traffic
• Work zone traffic control techniques
• Device Usage
• Safety devices
• Traffic control devices
• Placement of traffic control devices
• Relevant OSHA Regulation
• 29 CFR 1926.21, Safety Training and Education

23
Worker Safety Consideration- WORKER SAFETY
APPAREL

• Workers near motor vehicle traffic should wear
  bright, visible clothing
• Relevant OSHA Regulation
• 29 CFR 1926.95, Criteria for Personal Protective
  Equipment

24
Worker Safety Consideration - TEMPORARY TRAFFIC
BARRIERS

• Barriers shall be placed along the work zone
  depending on
• Lateral clearance of workers from adjacent
  traffic
• Speed of traffic
• Duration and type of operations
• Time of day
• Volume of traffic
• Relevant OSHA Regulations
• 29 CFR 1926.200(g), Traffic Signs
• 29 CFR 1926.201, Signaling
• 29 CFR 1926.202, Barricades

Concrete Barriers
25
Worker Safety Consideration SPEED REDUCTION
MEASURES

• Speed of passing motorists may be influenced by
• Regulatory speed zoning
• Funneling
• Use of law enforcement
• Lane reduction
• Presence of flaggers

26
Worker Safety Consideration PLANNING THE
ACTIVITY AREA

• Plan internal work space and activities
• Minimize the use of backing maneuvers of
  construction vehicles
• Minimize interactions between on-foot workers,
  equipment and trucks
• Minimize worker exposure to risk
• Develop internal traffic control plan and
  operations
• Refer to Module 2 Safe Operations and Internal
  Traffic Control in the Work Space

27
Worker Safety Consideration PLANNING FOR
WORKER SAFETY

• Hazard assessment should be conducted based on
• Characteristics of work site
• Job classifications required in the work area
• Must comply with all relevant OSHA regulations
• Assess worker risk exposures for each job site
  and job classification
• 29 CFR 1926.20, General Safety and Health
  Provisions
• 29 CFR 1926.20 (b) (2)

28
Optional Worker Safety Elements

• Shadow Vehicle with Impact Attenuator
• Road Closure
• Police enforcement
• Additional Lighting
• Special Devices
• Rumble strips
• Changeable message signs
• Hazard identification beacons
• Flags
• Warning lights
• Intrusion warning devices

Rumble strips
29
Optional Worker Safety Elements - SHADOW VEHICLE

• Common for mobile and constantly moving operations

• Should be equipped with
• Appropriate lights
• Warning signs
• Rear-mounted impact attenuator

Shadow vehicle with rear mounted crash attenuator
30
Truck Mounted Attenuator
Crash with a truck with a truck mounted impact
attenuator
Crash with a truck without an impact attenuator
31
Optional Worker Safety Elements - ROAD CLOSURE

• Reduce worker vulnerability to risk of injury
• Provide more spacious areas to conduct work
  activities
• Eliminate threat of intruding vehicles from
  passing traffic
• Aid in faster project
• completion

Freeway closure for one direction of traffic
32
Optional Worker Safety Elements - USE OF POLICE
ENFORCEMENT

• Police units may be stationed in a work zone to
• Heighten awareness of passing motorists
• Improve safety through work zone by enforcing
  speed limits

33
Optional Worker Safety Elements - LIGHTING

• Additional lighting should be provided at work
  zones that operate during the night

• Nighttime work requires extra caution due to
• Poor night time visibility
• Impairment of workers related to fatigue
• Impairment of drivers

Nighttime work is common in highway/street
construction projects
34
Sample Work Zone Traffic Control Layout

• For a Single Lane Closure as per MUTCD
• Pre-construction speed limit is 70 mph

KEY
Note Distance in feet, drawing not to scale
Channelizing Devices
Sign Location
35
Work Zone Traffic Control

• MUTCD provides minimum requirements
• Various demanding situations may warrant enhanced
  safety precautions, such as
• Nighttime work
• Inclement weather conditions
• Unusual roadway geometry and environment
• Combinations of the above
• Going beyond existing standards/guidelines may be
  necessary to ensure highest levels of traffic and
  worker safety

36
Work Zone Traffic Control Hazards and Injury
Prevention Techniques
37
Hazards of Work Zone Traffic Control
Common Hazards

• Passing motorist intruding into the work space
• Hazards related to flagging
• Nighttime hazards

38
Hazards of Work Zone Traffic Control
Causal Factors

• Conditions unexpected by the moving traffic
• Violation of driver expectancy
• Conditions unexpected by the workers
• Aggressive drivers
• Unplanned work zone/activity
• Injuries can occur due to
• Motorists mistakes
• Workers mistakes
• Deficiencies in the work zone environment

39
General Preventive Measures

• On-foot workers
• Use portable radio communication equipment

• Traffic Control
• Use additional warning devices
• Maintain signs properly
• Use Proper lane markings

• Flaggers
• Use a flashing slow/stop paddle

• Law enforcement
• Use officers and radar surveillance for traffic
  speed control

40
Hazard Passing Motorists Intruding Into Work
Space

• Causes of Hazards
• High approach speed
• Improper geometry of the lane shift
• Improper traffic control
• Inadequate information system

No physical separation between work space and
traffic lane

• Hazard mitigation measures
• Use of proper speed reduction methods
• Proper design of the wok zone
• Provide effective traffic control measures

41
Hazard Passing Motorists Intruding Into Work
Space
Preventive Measures

• Exceed minimum standards/guidelines for traffic
  control
• Rumble strips
• Lane drop arrows
• Lighted raised pavement markers
• Radar triggered speed display
• Safety warning system
• Combinations of the above

Truck may intrude into the work zone
42
Sample Work Zone Traffic Control Layout With
Additional Safety Features

• For a Single Lane Closure

Retroreflective Raised
Pavement Markers
Radar Triggered
Your
Your
White Pavement
Temporary Rumble
Increase Buffer
Speed is
Speed is
Speed Display
XX
XX
Strips
Markings Symbol
Area
REDUCED
REDUCED
SPEED
SPEED
SPEED
SPEED
LIMIT
LIMIT
XX
XX
XX
XX
AHEAD
AHEAD
Flashing
R2
-
5b
G20
-
2
G20
-
2
R2
-
1
W20
-
5
W4
-
2R
W21
-
4
Arrow Panel
D
D
D
D
D
D
D
L
Truck Mounted
Attenuator
43
Innovative Technologies for Hazard Control

• Vertical safetycade
• CB wizard alert system
• Radar triggered speed display
• White lane drop arrows
• Lightguard lighted raised pavement markers
• Removable orange strips
• Flashing slow/stop paddle

44
Vertical Safetycade

• Designed to replace standard channelizing devices
• Benefits
• Better visibility
• More positive guidance
• Greater portability
• Improved recoverability
• Collapsible frame

Vertical Safetycades
45
CB Wizard Alert System

• Trailer-mounted system
• Broadcasts a recorded message to all CB-equipped
  motorists
• Notify drivers of downstream work zones
• Allows truck drivers to lower their speeds in
  advance of work zone

CB Wizard Advanced Warning Unit
CB Wizard Unit
46
Radar-Triggered Speed Display

• Back-lit dynamic speed display
• Standard speed limit sign
• Strobe flash (optional)
• Strobe will flash when a vehicle exceeds a
  certain speed
• Trailer mounted

47
Lane Drop Arrows

• Alert driver in advance of lane closure
• Encourage drivers to reduce speed and move to the
  open lane

48
Lightguard Lighted Raised Pavement Markers

• Provide greater visibility in work zones
• Can be
• Flashing lights
• Racing lights
• Steady-burn lights

Without Lightguard Lighted Raised Pavement Markers
With Lightguard Lighted Raised Pavement Markers
49
Removable Orange Rumble Strips

• Alert motorists of a work zone
• Benefits
• Highly visible
• Repeating rumble sound
• Vibration of the steering wheel
• Easy to install and remove
• Reduce approach speed

50
Flashing Slow/Stop Paddle

• Consists of a standard paddle with a strobe light
  mounted on its face
• Increases flagger visibility to passing motorists

51
Hazard Flagging Operation

• 20 flaggers die each year from being struck by
  a motorist

Nonstandard paddle height

• Flagging can be hazardous as a result of
• High speed of passing traffic
• Aggressive drivers in traffic stream
• Insufficient stopping sight distance for
  motorists
• Improper procedures used by flaggers
• Not wearing personal protective equipment
• Inattention
• Use of nonstandard equipment
• Improper flagging techniques
• Hazardous environmental conditions
• Fog, obstructions, wet pavements

Paddle inclined
52
Injury Prevention Techniques for Flaggers

• Wear high visibility clothing
• Appropriate for expected weather (rain gear, warm
  coat, etc.)
• High visibility hard hat
• Use a standard SLOW/STOP paddle or flag
• Flags are for emergency purposes only

53
Injury Prevention Techniques for Flaggers

• STAY ALERT, keep focused on your work
• Stand alone on shoulder in clear view, not in the
  open traffic lane
• Plan an escape route for emergencies
• Stay in communication with the other flaggers
• Treat motorists with respect
• Obtain proper training for flaggers, including
  safety training

54
Injury Prevention Techniques for Flaggers

• Flaggers must avoid
• Standing where the flagger can be hit by a
  vehicle
• Standing in the shade, around a sharp curve
• Standing in a group
• Standing near equipment
• Making unnecessary conversation
• Reading or day dreaming
• Listening to music or using ear phones
• Turning their back to approaching traffic

55
Hazard Nighttime Traffic Control

• Nighttime traffic control is more challenging
• Poor visibility for drivers
• Poor visibility for workers
• Impaired or drowsy drivers
• Sleep deprived workers

56
Nighttime Traffic ControlInjury Prevention

• Use special precautions for nighttime traffic
  control
• Retro-reflective clothing
• Flashing lights on body/clothing
• Retro-reflective tape on equipment
• Good work area lighting

57
Summary of the Module

• Work zone traffic creates serious hazards for
  motorists and workers
• Provisions of MUTCD may not be sufficient for
  preventing injuries/fatalities of on-foot workers
• Additional injury prevention techniques should be
  implemented to prevent injuries to on-foot
  workers
• Positively guiding traffic through the complex
  work zone is the key to safety

58
End of Module 1