U.S. Department of Transportation
Federal Highway Administration
1200 New Jersey Avenue, SE
Washington, DC 20590
Yodock Wall – Yodock units have been crash tested in three ways: as stand alone barricade units, as longitudinal channelizers, as shown here, and with the addition of a steel box beam rail, as barriers. When deployed like this, water filled units are a good substitute for a line of drums. They are not redirective vehicle barriers, as the vehicle may penetrate a longitudinal channelizing barricade. Forces on the vehicle occupants must be below the limits acceptable for a barrier impact.
Roadguard (left) with highway kit and Triton barrier (middle, and right) internally reinforced. Both of these proprietary systems have been accepted as BARRIERS. For water filled units to actually perform as a barrier, you must have a steel framework, internal or external.
The typical pin and loop design that has been in use for years needs to be beefed up in order to meet current crash test criteria. Failures of pin and loop designs have been caused by thin pins pulling out of the loops, loops breaking, or concrete fracturing due to lack of reinforcement. There are nearly a dozen successfully crash tested designs of portable concrete barriers, and they are posted on our web site.
Energite III and Quadguard CZ Sand barrel attenuators are initially low-cost but they need nearly total replacement after a hit. More sophisticated attenuators like the Quadguard CZ are quite expensive, but can be restored quickly and cheaply, sometimes without the need to replace any parts at all.
TMAs are optional devices, but in order to be acceptable for use they must meet NCHRP Report 350 Test Level 2 criteria at a minimum.
Federal Aid research funds were used to develop a non-proprietary work zone truck-mounted attenuator. On July 13, 1995, FHWA accepted the Connecticut Truck Mounted Attenuator as NCHRP Report 350 TL-2 Truck Mounted Attenuator.
The Connecticut DOT first tested the concept over 30 years ago and has found it to be excellent life-saving device. The CT DOT offers free plans for this generic, non-proprietary work zone safety system. Full details are linked at http://www.ct.gov/dot/ctma.
FHWA - HSA-10
400 Seventh Street, SW
Washington, DC 20590