Evaluation of the guard rail energy absorbing terminal (G-R-E-A-T) impact attenuator : final report.

Research Project No. 79-3G(B)
This short report evaluates as many aspects of the Guard Rail Energy Absorbing Terminal (G-R-E-A-T), a vehicle attenuator, as possible. The system was first installed on a particular bridge in September 1979 and was evaluated for three years. No impact occurred during that interval, so an evaluation of impact wortiness could not be assessed. However, installation and its resistance to weather are evaluated.
The installation presented no problem. However, about two years after its installation, the system's energy absorbing modulus had to be replaced because of moisture damage. A new design of the energy absorbing cartridge was installed. They have shown no damage thus far.