TRUCK MOUNTED ATTENUATOR SECTION 808
443 SECTION 808 — TRUCK MOUNTED ATTENUATOR
808.1Description.
This work consists of providing and maintaining truck mounted attenuators (TMA).
808.2Materials.
Not applicable.
808.3Construction.
A.Positioning the TMA:
1.Use the TMA in accordance with the DE MUTCD .
2.Position the TMA so the distance between the front bumper of the shadow vehicle and the
closest point of the work area is in accordance with the manufacturer’s roll -ahead recommendations. Keep a copy of the manufacturer’s recommended roll -ahead distance in the shadow vehicle at all times.
3.Place the TMA so the equipment does not block driveways, commercial vehicle entrances, or
streets and does not interfere with sight distance restrictions unless approved by the engineer.
4.Position the TMA in the full down position and set the display for the arrow board to the
appropriate designation based upon the type and location of work.
5.Use additional TMAs if the distance between what the TMA is protecting and the front of the
shadow vehicle is at least twice the recommended roll ahead distance. 808.3.1 Equipment.
A.Provide a shadow vehicle, driver, and truck or a TMA.
1.Provide a shadow vehicle with a valid registration, a registration number plate, current
inspection documentation, weight verification, and proof of insurance.
2.Provide operators that possess a valid driver’s license of the required class to operate the
shadow vehicle.
3.Provide truck or trailer mounted style TMA meeting the crash testing requirements of MASH .
a.Submit the latest version of MASH eligibility letters in accordance with Section 801.2.
b.Ensure a Type I TMA meets the requirements of Test Level 2. Do not use on roadways with
posted speeds greater than 40 miles per hour.
c.Ensure a Type II TMA meets the requirements of Test Level 3.
4.Attach the TMA to the back of the shadow vehicle in accordance with the manufacturer’s
recommendations.
5.Provide a shadow vehicle in accordance with the TMA manufacturer’s recommendations for
weight requirements.
a.Keep a weight ticket from a certified scale house in the vehicle at all times indicating the
weight of the shadow vehicle. TRUCK MOUNTED ATTENUATOR SECTION 808
444 b. Secure the shadow vehicle’s counterweight in accordance with Federal motor vehicle guidelines, so the counterweight does not shift when braking or cause an impact with the TMA.
6.Cover the back of the TMA with 6 -inch diagonal inverted “V” stripes of alternating yellow
retroreflective and black material, placed 6 -inches apart.
7.Provide a large rotating amber beacon or strobe light on the shadow vehicle in accordance with
the DE MUTCD .
8.Provide a Type C arrow board on the TMA in accordance with the DE MUTCD and Section 802.
For proper acceptance, provide documentation showing that the TMA and arrow board combination meets MASH crash testing criteria.
9.Operate the TMA and arrow panel from the cab of the shadow vehicle. Ensure that the operator
can raise and lower the TMA and the arrow board and that the operator can change the display on the arrow board from inside the cab.
10.Make the shadow vehicle and the TMA available for inspection upon request before starting
work.
B.Maintain the truck or TMA as follows:
1.Repair and replace the TMA or shadow vehicle should either vehicle become damaged. Submit
certification of repairs to the engineer before putting the damaged vehicle back in service.
2.Make arrangements with the TMA supplier to have replacement components for the TMA
readily available for immediate repair.
3.Remove the TMA immediately from the project upon discovery, or notification of, damage and
replace with an operable TMA or suspend the work requiring the TMA.
808.4Method of Measurement.
The Department will measure TMAs as the actual number in place on the roadway and protecting active construction operations per calendar day. A calendar day consists of any approved usage within 24 - hours of placing the device. The Department will measure each TMA only once in a 24 -hour period, regardless of how many times the contractor relocates the TMA within the same project. When the contractor uses a TMA for part of a day, the Department will measure it as 1 each day.
808.5Basis of Payment.
A.The Department will pay for truck mounted attenuator at the contract unit price per each day.
Price and payment constitute full compensation for:
1.Providing, positioning, and maintaining the TMA and Type C arrow boards;
2.the shadow vehicle and driver;
3.repair or replacement of the unit; and
4.removal.
TRUCK MOUNTED ATTENUATOR SECTION 808
445 ITEM DESCRIPTION UNIT 808001 PROVIDE AND MAINTAIN TRUCK MOUNTED ATTENUATOR, TYPE I EA-DY 808002 PROVIDE AND MAINTAIN TRUCK MOUNTED ATTENUATOR, TYPE II EA-DY TEMPORARY IMPACT ATTENUATOR SECTION 809
446 SECTION 809 — TEMPORARY IMPACT ATTENUATOR
809.1Description.
This work consists of providing, installing, relocating, maintaining, and removing temporary impact attenuators (TIA).
809.2Materials.
Not applicable.
809.3Construction.
809.3.1 Equipment.
A.TIAs.
1.Provide TIAs of the type specified in the contract in accordance with Section 724.
2.Provide ASTM D4956 Type IV retroreflective sheeting on the nose of the TIA facing traffic.
Provide sheeting with:
a.Alternating 3 -inch minimum wide yellow and black stripes;
b.stripes positioned at a 45 -degree angle pointing down towards the side where traffic will pass
the impact attenuator; and
c.covering the entire TIA nose.
3.Meet MASH crash testing requirements .
4.Select TIAs from the Design Resource Center Approved Products List.
5.Provide the engineer with a written description of the TIAs planned for use. Submit TIA shop
drawings and manufacturer’s installation instructions.
6.Provide and maintain the availability of 1 complete stand -by replacement TIA of each type used
at a location approved by the engineer .
B.Sand Crash Cushions.
1.Provide sand crash cushions in accordance with the contract consisting of an array for the design
speed of the roadway.
2.Use sand crash cushions only when specified in the contract or approved by the engineer.
3.For the sand and salt mixture in sand crash cushions, provide:
a.Clean, loose sand with a density of 100 pounds per cubic foot and a moisture content of no
more than 3 percent.
b.A mixture in accordance with manufacturer’s recommendations. If no recommendations are
available, the mixture must contain 10 to 20 percent rock salt by volume.
c.Certification to the engineer that the sand and salt mixture meets these requirements before
installing the sand crash cushion array.
4.Provide 1 complete stand -by replacement sand crash cushion array.
809.3.2 TIA and Sand Cushion Placement, Repair, Relocation, and Removal.
Source: Delaware Standard Specifications for Road and Bridge Construction, 2025 Edition. Pages 453–456 of 779.