Temporary Portable Rumble Strips

John D. Hancock, P.E.

State Construction Engineer

Test Project

Project M004907 Floyd County

• The project consisted of 3.282 mile of single surface treatment paving and shoulder rehabilitation on SR 20 beginning at the Alabama state line and extending east to SR 100.

Test Project

Project M004907 Floyd County

• The Work consisted of asphalt patching, single surface treatment with leveling, topping with 9.5 asphalt concrete, and shoulder building.

Test Project

Project M004907 Floyd County

• This section of SR 20 is a rural two lane roadway. Paved shoulders are 2 feet but unpaved shoulders are often 12 feet or more. Overall sight distances were good at ½ mile or better. The speed limit was 55 mph. There were several intersections and several driveways but no traffic signals.

Test Project - M004907

• The ADT is 6,710.

• Truck traffic during the day could peak at 50% to 60%. Approximately 20% of the truck traffic was logging trucks.

• Rush hour went from 08:00 a.m. to 10:00 a.m., both west and east bound.

• Rush hour westbound could start as early as 2:30 p.m..

Traffic Volume

Installation

Manufacturer recommendation for the placement during flagging operation.

Installation

Used GDOT Special Detail

• This standard was developed using the ASSTA “Guidance for the Use of Temporary Rumble Strips in Work Zone”.

• The difference is we did not use PSS spacing “B”.

• The last rumble strip in an array is placed at the sign.

• Increase the spacing of the rumble strips to 15 feet.

• Orange color rumble strips for the second array

Work Zone Signs

Road Work Signs

Work Zone Signs

Road Work Signs

Work Zone Signs

Road Work Signs

Work Zone Signs

Flagging operation signs

Work Zone Signs

Flagging operation signs

Deployment

Eastbound SR 20

ObservationsTraffic Back-up Beyond the TPRS

• The rumble strips provided no benefits

• Many cars would start and then slow/stop at the rumble strips

• Caused semi-trucks to downshift gears

• Speeds through the queues were reduced and the queues never emptied

• Black or orange color did not make a difference

Observations

Trucks

• The trucks’ back tires could wheel hop going over the strips.

• The temporary rumble strips did not move.

• Trucks driving over the rumble strips produced a loud noise due to wheel hop

• Trucks drivers, i.e. asphalt hauler, who had been previously through the site were more likely to avoid the strips

Observations

Effectiviness

• 80% - 90% of vehicles did brake and slow at the rumble strips

• Semi-trucks and logging trucks were more likely to avoid the strips

• Contractor became better at moving the TPRS

• There appeared to be a learning curve for the traveling public. Fewer vehicles tried to avoid the temporary rumble strips as work progressed.

• Temporary rumble strips did slow traffic

Observations - Video

Survey Card

• 3 pilot projects

• 250 survey cards per project

• Handed out to motorist

Survey Card

Survey Card

Survey Card

Survey Text

• The Georgia Department of Transportation is working to ensure the safety of our workers and the traveling public in work zones. As a result, the Department is testing the use of Temporary Portable Rumble Strips (TPRS) on three projects across the state to gauge their effectiveness on getting driver’s attention and slowing traffic in work zones where flaggers are present.

• These TPRS will be located approximately 500 feet before a flagger, on a two-lane road and will be in place six to eight hours each day. The test project will last 30 – 60 days, beginning March XX, 2017. Please circle one answer below.

Survey Card

Survey Text

• Did the TPRS get your attention and cause you to slow down?

• Did the TPRS give you enough of an advance warning so that you could slow down?

• Did the TPRS cause you to pay attention to your surroundings?

• Do you think TPRS would be effective in keeping flaggers safe on future projects?

Survey Card

Survey Response

• PI NO: M005042 Warren, McDuffie (D2)

116 returned – all replies were “YES”

• PI NO: M005325, Miller County (D4)

100 returned – all replies were “YES”

• PI NO: M005155 Dooly, SR 257 (D3)

27 Responses – all replies were “YES”

Path Forward

Recommend locations

• Use of TPRS on two lane resurfacing projects

• Rural locations

• Higher speeds are possible

Questions?