Work Zone - Appendix A
Appendix E: 2006 Guidelines to Establish Speed Limits in Work Zone
(Updated 12/3/2020)
Work Zone Speed Limit Procedure:
Condition 1 – Roadside Activity
Work activities, workers, materials, and equipment that are more than 15 ft from the edge of the traveled way.
Typical Applications
- Construction
- Cleaning drainage
- Landscaping work
- Structural Work
- Utility work
- Reworking ditches
- Fencing work
Speed Limit
No reduction
There should not be a reduction to the regulatory speed limit, unless unusual situations create hazardous conditions for motorists, pedestrians, or workers. A temporary Traffic Control Order (TCO) is required prior to the start of work when speed reductions are required.
Condition 2 – Roadside Activity
Work activities, workers, materials, and equipment that encroach on the area closer than 15 ft, but not closer than 2 ft to the edge of the traveled way.
Typical Applications
- Construction
- Culvert extensions
- Guardrail installation
- Cleaning drainage
- Structural work
- Reworking ditches
- Sign installation
- Shoulder work
- Utility work
- Side slope work
- Landscape work
Speed Limits (Where Existing Speed Limits are 50 mph or Higher)
- Where workers are present with channelizing devices = 45 mph.
- Where workers are present with concrete barriers = a maximum 10 mph reduction or as geometric and physical conditions dictate.
- No workers present = a maximum 10 mph reduction or as geometric and physical conditions mandate.
Speed Limits (Where Existing Speed Limits are 45 mph or Lower
- All conditions = a maximum of 10 mph reduction or as geometric and physical conditions mandate.
- No speed reductions where existing speed limits are 30 mph or less.
A temporary traffic control order is required prior to starting work if speed reductions are required.
If speed reductions are used, the factors used to determine the reduced speed shall be noted in the plans.
Example Factors for Speed Reductions During Non-Work Periods or When Barrier Wall is Present
- Horizontal curvature that might increase vehicle encroachment rate (could include mainline curves, ramps, and turning roadways).
Condition 3 – Lane Encroachment
Work activities, workers, materials, and equipment that encroach the area from within 2 ft of the edge of the traveled way to 2 ft into the lane from the edge of the traveled way. Lane closures shall be required if the remaining lane is less than 10 ft in width, excluding the channelizing devices.
Typical Applications
- Roadway construction
- Guardrail installation
- Utility work
- Shoulder work
- Joint work
Speed Limits (Where Existing Speed Limits are 50 mph or Higher)
- Where workers are present with channelizing devices = 45 mph.
- Where workers are present with concrete barriers = a maximum 10 mph reduction or as geometric and physical conditions dictate.
- No workers present = a maximum 10 mph reduction or as geometric and physical conditions mandate.
Speed Limits (Where Existing Limits are 45 mph or Lower)
- All conditions = a maximum of 10 mph reduction or as geometric and physical conditions mandate.
- No speed reductions where existing speed limits are 30 mph or less.
No traffic control order is required.
If speed reductions are used, the factors used to determine the reduced speed shall be noted in the plans.
Factors for Speed Reductions During Non-Work Periods or When Barrier Wall is Present
Horizontal curvature that might increase vehicl encroachment rate (could include mainline curves, ramps, or turning roadways).
- Barrier or pavement edge drop-off within 2 ft of traveled way.
- Reduction in sight distance.
- Unique or special conditions.
Condition 4 – Short Duration and Mobile Activity on Shoulder
Work activities, workers, materials, and equipment that require a short duration or mobile activity on the shoulder.
Typical Applications
- Utility work
- Delineator installation
- Shoulder and slope work
- Landscape work
- Temporary and permanent signing
Speed Limit
No reduction
Example Factors of Speed Reductions During Non-Work Periods or when Barrier Wall is Present
None
Condition 5 – Lane Activity
Work activities, workers, materials, and equipment that occur in traffic lanes.
Typical Applications
- Roadway construction
- Pavement resurfacing
- Pavement repair
- Temporary pavement marking
- Utility work
- Bridge repair
- Widening
Speed Limits (Where Existing Speed Limits are 50 mph or Higher)
- Where workers are present with channelizing devices = 45 mph.
- Where workers are present with concrete barriers = a maximum 10 mph reduction or as geometric and physical conditions dictate.
- No workers present = a maximum 10 mph reduction or as geometric and physical conditions mandate.
Speed Limits (Where Existing Speed Limits are 45 mph or Lower)
- All conditions = a maximum of 10 mph reduction or as geometric and physical conditions mandate.
- No speed reductions where existing speed limits are 30 mph or less
No traffic control order is required.
If speed reductions are used, the factors used to determine the reduced speed shall be noted in the plans.
Example Factors of Speed Reductions During Non-Work Periods or when Barrier Wall is Present
- Lane width reduction of 1 ft or more with a resulting lane width less than 10 ft.
- Traffic control devices encroaching on a lane open to traffic or within a closed lane, but within 2 ft of the edge of the open lane.
- Reduced posted speed for taper length or speed change lane length.
- Barrier or pavement edge drop-off within 2 ft of traveled way.
- Reduced posted speed of horizontal curve.
- Reduced posted speed for stopping sight distance.
- Traffic congestion created by lane closure.
- Unique or special conditions.
Condition 6 – Temporary Detour
Some activities require a temporary detour to be constructed. Existing routes used for detours should use established speed limits in place.
Typical Applications
- Roadway construction
- Sub-grade restoration
- Bridge construction
- Culvert repair
Speed Limits
No reduction
Example Factors of Speed Reductions During Non-Work Periods or When Barrier Wall is Present
None
Design Guideline Exceptions or Adjustments
- For projects involving temporary traffic signals, no speed limit reductions shall be signed in advance of the temporary traffic signal. If the open traffic lane is restricted in width, signing for a reduced lane width with a speed advisory panel shall be used.
- On longer projects, refer to the note sheets on the maintaining traffic typicals for additional speed limit sign placements.
- Additional exceptions will be dealt with on an as needed basis through MDOT and within contract documents.