Preliminary Study on Snowplow Survivability of Guardrail Terminals

Abstract

FHWA has asked Alaska Department of Transportation and Public Facilities (DOT&PF) to fix damaged longitudinal and end sections of guardrail throughout Alaska's road system. The proposed research evaluates W-beam guardrail end terminals (GET) which are installed along roads in heavy-snow areas of Alaska. Primarily, it is important for DOT&PF to determine how well GET withstand loads generated during snow plowing and blowing operations. Based on this preliminary study, the following conclusions are made (1) Anecdotal evidence indicates that the newly installed SRT-350s are not very forgiving (because they are designed to be crash-friendly), and relatively minor contact between the snow removal equipment and the terminal may result in terminal failure and at least some damage. (2) There are two types of damage to the newly installed SRT-350s; (a) damage due to contact between the snow removal equipment and the terminal; and (b) damage resulting from the pressure of the snow (snow-only contact). The first type is the most likely damage observed in field visits. The damage due to snow-only contact can occur in heavy snow area. (3) Except in heavy snow area, the average replacement rate for newly installed SRT-350s can be reduced to about the same level as the traditional BCTs if the snowplow operator learn to respect the new terminals more and provide them with a wide berth. To achieve this, it is very important to mark the end of the terminal as well as the beginning of the flare of the terminal. With both locations marked, an operator can carefully avoid the entire length of the terminal. (4) Further research is needed to investigate guardrail end terminals which are more durable or are easily repaired.