PROBLEM IDENTIFICATION AND CORRECTION BY LOCATION OF PROBLEM

LOCATION

POSSIBLE PROBLEM

POSSIBLE TRAFFIC CONTROL CHANGE

1

Accidents or incidents occurring in the warning or approach area of the work

zone

Insufficient advance warning signs

· Add warning signs

· Increase size of advance warning signs

· Use changeable message signs

Speeds too high or high variance in speeds

· Add advisory speed signs

· Provide extra enforcement

· Install rumble strips

Improper flagging technique

· Train flaggers

· Move flaggers upstream

Insufficient work zone traffic capacity

· Provide alternate routes

· Change work schedule to exclude peak traffic periods

Signs not visible at night

·Mount signs at correct height above roadway

· Install flashing warning lights on signs

· Replace signs not meeting visibility requirements

· Illuminate signs

Improper lane changes

· Lengthen taper

· Move taper position upstream

2

Accidents or incidents occurring in the transition  area of the work zone

Insufficient advance warning

· Add advance warning signs

· Increase size of advance warning signs

· Use variable message sign

Lack of sufficient sight distance to taper

· Move taper upstream to increase sight distance

Improper merging at lane closures

· Move taper upstream to increase sight distance

· Lengthen taper

Insufficient work zone capacity

· Provide alternate routes

· Change work schedule to exclude peak traffic periods

Transition not visible at night

· Illuminate or reflectorize channeling devices

· Add temporary pavement markers

Speeds too high or high variance in speeds

· Provide extra enforcement

· Add advisory speed signs

Advance warning signs too far upstream from transition

· Move warning signs more frequently

3

Accidents or incidents occurring on curves

Inadequate design for prevailing vehicle speeds

· Improve edge line delineation

· Add advisory speed plates 

4

Accidents or incidents occurring in the work area of the work zone

Workers or equipment too near traffic station

· Move equipment

· Instruct workers to wear hard hats and safety vests

· Instruct workers to stay as far as possible from traffic stream

· Install Highway Advisory Radio

Speeds too high or high variance in speeds

· Install rumble strips

· Provide extra enforcement

· Add advisory speed signs

Access and egress of work vehicles into traffic stream

· Relocate work vehicle access and egress points

· Have contractor furnish flaggers

Insufficient work zone traffic capacity

· Provide alternate routes

· Change work schedule to exclude peak traffic periods

· Install Highway Advisory Radio

· Reduce length of work area

5

Accidents or incidents on two-lane, two-way traffic operations on divided highways

Passing in no-passing zone

· Provide extra enforcement

· Maintain tubes on centerline of two-way section

· Use changeable message signs

Insufficient work zone traffic capacity

· Provide alternate routes

· Use changeable message signs

· Notify media

6

Accidents or incidents on one lane sections with alternating direction traffic operations

Excessive vehicle queues and delays

· Reduce length of section

Improper flagging technique

· Train flaggers

· Move flaggers upstream

7

Accidents or incidents occurring at median crossovers

Insufficient crossover delineation

· Remove old pavement markings

· Install new pavement markings

· Install raised pavement markers

Speeds too high or high variance in speeds

· Provide extra enforcement

· Add advisory speed signs

Shifting of cargo loads in trucks

· Provide extra enforcement

· Add advisory speeds signs

· Install raised pavement markings

 

 

PROBLEM IDENTIFICATION AND CORRECTION BY ACCIDENT TYPE

ACCIDENT TYPE

POSSIBLE PROBLEM

POSSIBLE TRAFFIC CONTROL CHANGE

1

Fixed object accidents

Narrow work zone roadway

· Widen roadway by moving channelizing devices or by using narrower devices

· Improve reflectivity and delineation of devices

Insufficient advance warning

· Move taper upstream to increase sight distance

2

Pedestrian accidents or incidents involving Pedestrians

Pedestrians on the roadway

· Install barriers between pedestrians and traffic

· Restrict pedestrian movements

Workers in or near traffic

· Install barriers between pedestrians and traffic

3

Truck accidents or Incidents involving trucks

Speeds too high or high  variance in speeds

· Provide extra enforcement

· Add advisory speed plates

· Use changeable message signs

· Notify media

Work zone roadway too narrow for large vehicles

· Provide truck detours

4

Head-on accidents or Passing conflicts

Divided highway with two-way traffic operations

· Shorten length of two-way traffic operation

· Maintain channelizing devices on centerline

· Provide extra enforcement

· Notify media

Slow-moving maintenance operations

· Require work train to allow vehicles to pass occasionally

· Improve signing and lighting of work vehicle

· Change work schedule to periods of lower traffic volume

5

Rear-end accidents or slow-moving vehicle conflicts

Insufficient work zone traffic capacity

· Provide alternate route

·  Change work schedule to exclude peak traffic periods

· Reduce length of work area

· Install warning signs

Poor work vehicle access or egress to traffic stream

· Change work vehicle access or egress points

· Have contractor provide flaggers

Improper flagging technique

· Train flaggers

· Move flagger upstream

High variance in vehicle speeds

· Provide reasonable speed limits

· Provide extra enforcement

6

Sideswipe same direction accidents, merging accidents, and lane change or slow-to-merge conflicts

Insufficient taper length

· Lengthen taper

· Position arrow board near start of taper

· Move taper upstream to increase sign distance

Insufficient acceleration lane length

· Lengthen taper

· Install yield or stop signs on on-ramp

· Close on-ramp

Incorrect taper placement

· Move taper upstream to increase sight distance

· Position arrow board near start of taper

7

Run-off-road accidents or shoulder encroachments

Narrow roadway

· Widen roadway

· Improve edge line delineation

· Provide extra enforcement

 

 

PROBLEM IDENTIFICATION AND CORRECTION BY TIME-OF-DAY/WEATHER CONDITIONS

TIME/WEATHER

POSSIBLE PROBLEM

POSSIBLE TRAFFIC CONTROL CHANGE

1

Night accidents

Poor visibility or delineation

· Illuminate or reflectorize channelizing devices

· Remove old pavement markings

· Add temporary raised pavement markings

· Add temporary pavement edge lines

Equipment or vehicles stored near roadway

· Store vehicles and equipment at location away from roadway

2

Accidents or incidents during periods of peak  traffic volume

Insufficient work zone traffic capacity

· Provide alternate routes

· Change work schedule to exclude peak traffic periods

Access and egress of work vehicles into traffic stream

· Relocate work vehicle access and egress points

· Have contractor provide flaggers

3

Accidents or incidents during weekend periods

Vandalized or stolen traffic control devices

· Furnish night watchman

· Increase routine police patrols

Trucks or recreational vehicles unable to negotiate curves

· Lengthen tapers

· Use changeable message signs

· Notify media

4

Accidents or incidents during inclement weather

Poor visibility or delineation

· Remove old pavement markings and replace with new pavement markings

· Install raised pavement markers

Poor drainage

· Improve superelevation

· Patch low pavement areas

· Prevent mud from washing onto roadway