• The Connecticut Impact Attenuation System (CIAS) is a highway safety device that meets the "Test Level 3" performance requirements for redirective-gating crash cushions.  These requirements were established by the Transportation Research Board [National Research Council] through the National Cooperative Highway Research Program.  The criteria are published and available free online in NCHRP Report No. 350, "Recommended Procedures for the Safety Performance Evaluation of Highway Features". 

• See Definitions of Gating and Non-Gating Terminals

• CIAS is a Unique Redirective-Gating Attenuator
  • Firstly, when a vehicle impacts near the back of the cushion, it "redirects" the vehicle away from the fixed object, so this is its redirective capability.
  • Secondly, the CIAS "captures" vehicles impacting at or near the nose and along its sides.  This is the gating capability of the CIAS.

• NCHRP Report 350 established three test levels for terminals and crash cushions based on impact speed.

• The CIAS was tested as a Level 3 Gating crash cushion under the following test numbers: 32, 33, 34 and 35

• Each test number has a specific vehicle size in Kilograms and a corresponding impact angle found in Table 3.2 of NCHRP Report No. 350.

A complete description of these tests can be found in section 3.2.2.2