S2This study was done to determine whether a finished line of guardrail posts could be installed rapidly with the new driver. For a realistic test, conditions typical of an actual guardrail post installation job were required. In addition to speed, it is necessary that guardrail posts be installed to specified tolerances. Therefore, posts were installed to meet the specifications of the State Road Commission of West Virginia for plumbness, alignment, spacing, and freedom from damage. Our main objectives in the study were: To compare the effectiveness of driving on a variety of sites. To compare the rates of installation by machine-driving and by the conventional hand-setting method. To evaluate the effect of post cross-sectional area on driving time.S3.