3 Testing Standards for Plastic Highway Barriers
Many tests are conducted at various levels to assess the strength of the longitudinal barriers whose main function is to prevent penetration of vehicles and to safely move the vehicle away from the road side. The products are tested at three levels.
Level 1: This is the test for the most basic product. In this test, a vehicle running at a speed of 50 km/hour (31mph) will impact the product at angles of 20-25 degrees. This basic crash test should be done to comply with the requirements of the National Cooperative Highway Research Program. The products failing this test should be scrapped or used for alternative purposes such as recreational sports or crowd control, but cannot be used as barriers at any other place. There are two sections which are examined in the process of passing the product. One of them is the part of the barrier designed to contain and redirect the errant vehicle which is known as the Length of Need and the other is the part of the barrier between the connecting sections known as the Transition. Once the product passes this test, it will be acceptable for low speed work zones and also low volume, low speed streets and highways. This is because the areas are less prone to vehicle penetration and also when they hit the barrier, they generally hit with speeds less than 50 km/hour in these areas as the speed limit is less in those areas.
Level 2: This is an intermediate level of crash testing. In this level, the vehicle running at a speed of 70 km/hour (43.5 mph) will impact the barrier at similar angles of 20-25 degrees as in level 1. Again, the two sections including the Length of Need and Transition are examined before passing the product. Once the barrier is qualified at this level, they can be accepted at most local and collector roads and many work zones. If the product fails at this level, it can be tested for Level 1 before scrapping it. If it passes level 1, it can be used in low volume, low speed streets and highways or some low volume work zones. This test was also conducted in November 1994 on Guardian 350 Highway Barriers and they passed the criteria for Level 2. It can be deduced that the Level 2 products need to be stronger and more shock resistant when compared to the Level 1 product as they are used in most local and collector roads where the speeds are generally higher than low speed streets and highways.
Level 3: This is the highest standard level of crash testing applicable to the longitudinal barriers. In this level, the vehicle running at a high speed of 100 km/hour (62.1 mph) will impact the product at the same angle 20-25 degrees as in the Level 1 and Level 2. As before, the two sections are examined (Length of the Need and Transition) at the end of the test before passing the product. It is to this level that most crash-tested safety features in use on U.S. highways have been qualified. Once a highway barrier qualifies at this level, they are acceptable for a wide range of high speed arterial highways .If they fail this test, then they will be tested on the earlier two levels to find the suitable position for the product. The product is placed accordingly.
Although these tests are of the utmost importance to the safety of roadways, construction zones, and various high traffic areas, many companies have found a loophole to circumvent these standards. Manufacturers and retailers of highway barriers are permitted to self-conduct these tests to ensure their products meet safety standards. However, often times these tests are not conducted and the company approves the barriers for level 3 usage regardless.
Tamis Corporation offers one of the select few highway barriers that have been tested approved on all 3 levels by an independent corporation making its products the safest and most reliable barriers in the industry. These Guardian Barriers have passed inspection and testing by The Texas Transportation Institute which currently stands as the largest transportation research agency in the United States. Here you can view video of the highway barrier deflection test results.
In 1994, The Texas Transportation Institute tested the Guardian 350 Highway Barrier at levels 1, 2, and 3, where it proved to be acceptable in each. In July 2002, the U.S. Department of Transportation’s Federal Highway Administration published a letter to the Armorcast Products Company stating that the modified design of the Guardian 350 Highway Barrier can be considered equivalent to the original Guardian Highway Barrier. Therefore, the Guardian 350 Highway Barriers can be used on the National Highway System (NHS) as National Cooperative Highway Research Program (NCHRP) Report 350 test level 3 (TL-3) traffic barriers.