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