IN-SERVICE PERFORMANCE OF HIGHWAY BARRIERS

All recorded guiderail and median barrier accidents on the New York State Highway System over a 2-year period were analyzed to evaluate performance of both new light-post barriers and older heavy-post barriers. Based on reports from 4,213 barrier accidents, the light-post designs appear to result in less severe injuries than the heavy-post types, which were erected through 1965. In most cases, light-post barriers were penetrated less often, and (as expected) trucks penetrated more frequently than cars. Most barrier end-sections, although penetrated more often than interior sections, performed satisfactorily in terms of injuries. Costs to repair accident-damaged barriers were lower for light-post barriers, even though greater lengths were damaged. A special study of barrier penetration resulted in raising the mounting height of rail elements to reduce barrier penetration. A subsequent investigation has confirmed that the frequency of barrier penetration has declined since this change. Accidents involving guiderail and median barrier installed in the medians of the New York State Thruway (324 accidents) and the Taconic State Parkway (286 accidents) were also reported for about 2 years; results confirm the excellent performance and low maintenance costs of light-post barriers.