DelDOT Standard Specifications 724: Impact Attenuator

724.1Description.

This work consists of providing and installing impact attenuators. Impact attenuator types are defined as follows:

A.Sacrificial – Devices designed for a single impact. These systems’ major components are destroyed

in impacts and must be replaced, but many of the other parts of the system can be reused.

B.Reusable – Contain some major components that may be able to survive most impacts intact and

can be salvaged when the unit is being repaired.

C.Low Maintenance – Devices that either suffer very little, if any damage, upon impact and are

easily pulled back into their full operating condition, or they partially rebound after an impact and may only need an inspection to ensure that no parts have been damaged, misaligned, or otherwise disabled.

724.2Materials.

A.Submit documentation requesting approval of impact attenuators 14-days before the start of

work. Submission requirements and instructions for source information are listed on DelDOT’s website: https://deldot.gov/Business/prodlists/index.shtml.

B.Provide impact attenuators to the latest MASH compliance or in accordance with contract,

selected from the approved products list. The list can be accessed by going to (https://www.deldot.gov/Business) and looking for the Approved Products List tab on the page.

C.Before installation, submit the choice of impact attenuator chosen for use on the project, with the

manufacturer’s installation instructions, to the engineer.

D.Provide an impact attenuator designed to leave no solid debris on the roadway after a head-on or

side angle impact. Refer to the contract for dimensional requirements, if any.

E.Impact attenuator designs:

1.Type 1 – Test Level 2 – Sacrificial

2.Type 2 – Test Level 2 – Reusable

3.Type 3 – Test Level 2 – Low Maintenance

4.Type 4 – Test Level 3 – Sacrificial

5.Type 5 – Test Level 3 – Reusable

6.Type 6 – Test Level 3 – Low Maintenance

724.3Construction.

A.Provide shop drawings to the engineer for approval before beginning installation. Assemble and

install the impact attenuator in accordance with the manufacturer’s requirements. Grade the area between the edge of pavement and the back of the impact attenuator in accordance with the manufacturer’s requirements.

B.Construct guardrail end treatment using applicable construction methods provided in Section

720.3Provide written certification, by installers certified by the attenuator manufacturer, that

the attenuator has been properly installed.

C.Notify the engineer and request acceptance after completing installation of the impact

attenuator. The engineer will inspect the installation. The Department will assume responsibility once the engineer accepts the installation. The engineer will notify the contractor to make repairs if an impact attenuator is damaged before final project acceptance and the engineer determines that the damage was not the result of contractor negligence.

724.4Method of Measurement.

A.The Department will measure the quantity of new impact attenuators as the number provided,

assembled, installed, and accepted.

B.The Department will measure the quantity of impact attenuators replaced due to damage not

caused by the contractor as the number provided, assembled, installed, and accepted.

724.5Basis of Payment.

A.The Department will pay the quantity of new impact attenuators at the contract unit price per

each. Price and payment will constitute full compensation for:

1.Pre-installation field meeting;

2.test pits;

3.providing and placing materials and components in accordance to the manufacturer’s

installation instructions;

4.shop drawings;

5.fabricating;

6.excavating;

7.burring of bolts;

8.backfilling;

9.grading;

10.compacting;

11.disposing of surplus materials and components

12.providing certifications; and

13.patching material around posts.

B.The Department will pay for a foundation when it is determined that the existing foundation does

not meet manufacture’s recommendations in accordance with the following section:

1.Excavation and backfill in accordance with Section 202;

2.Saw cutting in accordance with Section 762; and

3.Pavement patching in accordance with Sections 401 or 503.

C.The Department will pay the quantity of damaged impact attenuators replaced and disposed of at

the contract unit price, if complete replacement is required, or at a negotiated price, if a partial replacement or repair is required. ITEM DESCRIPTION UNIT 724001 PERMANENT IMPACT ATTENUATOR, TYPE 1 EA 724002 PERMANENT IMPACT ATTENUATOR, TYPE 2 EA 724003 PERMANENT IMPACT ATTENUATOR, TYPE 3 EA 724004 PERMANENT IMPACT ATTENUATOR, TYPE 4 EA 724005 PERMANENT IMPACT ATTENUATOR, TYPE 5 EA 724006 PERMANENT IMPACT ATTENUATOR, TYPE 6 EA 724008 PERMANENT IMPACT ATTENUATOR, WIDE BAY, TYPE 2 EA 724009 PERMANENT IMPACT ATTENUATOR, WIDE BAY, TYPE 3 EA 724010 PERMANENT IMPACT ATTENUATOR, WIDE BAY, TYPE 5 EA 724011 PERMANENT IMPACT ATTENUATOR, WIDE BAY, TYPE 6 EA

Referenced in this section

Sections that cite this one

809TEMPORARY IMPACT ATTENUATOR

IMPACT ATTENUATOR in other states

Kansas 811 · Impact Attenuator

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Source: Delaware Standard Specifications for Road and Bridge Construction, 2026 Edition. Pages 415–0 of 786. View official source ↗

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723 CONCRETE BARRIER

727 FENCE

724IMPACT ATTENUATOR

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