TMA guidelines & compliance

1 General

The primary objective of these guidelines is to provide standard guidance for the application of a TMA to be used on public roads. Refer to the relevant figure for the use of a TMA at road works.

2 Definitions

• TMA — refers to a truck-mounted attenuator.
• User — the contractor or agency using the TMA (whether self-owned or rented) on public roads with a posted speed of 70 km/h or more.
• Operator — a person trained and certified by the TMA manufacturer's authorised trainer or centre to correctly operate the TMA. The operator may also double as the shadow-vehicle driver.
• Shadow Vehicle — the LTA-approved truck on which the TMA is mounted.
• NCHRP — the National Cooperative Highway Research Program, commissioned by the American Association of State Highway and Transportation Officials and the US Federal Highway Administration.
• MASH — the Manual for Assessing Safety Hardware; the rewrite of NCHRP 350, reviewed by the AASHTO Technical Committee on Roadside Safety (TCRS).

3 Compliance

A truck-mounted attenuator unit mounted on the shadow vehicle shall meet both the mandatory and optional requirements stated in the NCHRP 350 Report TL-3, or the AASHTO Manual for Assessing Safety Hardware TL-3 (MASH).

The TMA shall have documentary evidence proving it has been successfully crash-tested following the procedures set out in NCHRP Report 350 or MASH. To allow the use of a collision attenuator or TMA on public roads, the user shall provide the following to LTA's Road Asset Regulation & Licensing (RARL) to demonstrate compliance:

1. A copy of the crash summary report, together with sequential photos from an ISO-certified test centre qualified to conduct NCHRP Report 350 / MASH impact tests; or
2. A copy of the acceptance letter or report from the United States Federal Highway Administration (FHWA).

4 Installation

The TMA shall be installed by a workshop authorised by the TMA manufacturer, in accordance with the drawings approved by LTA's Vehicle Approval & Control (VAC).