Testing and Evaluation of the W-Beam Transition (on Steel Posts with Timber Blockouts) to the Vertical Flared Back Concrete Bridge Parapet (FHWA-RD-96-200)

The W-beam transition is one of the most commonly used transition designs on the Nation's highways. The transition design has successfully met all evaluation criteria set forth in National Cooperative Highway Research Program (NCHRP) Report 230. However, with the adoption of NCHRP Report 350 by the Federal Highway Administration (FHWA) as the official guidelines for crash testing of roadside safety features, it became necessary to reevaluate the transition design to the new guidelines. Of particular importance is the replacement of one of the design test vehicles specified in NCHRP Report 230, the 2044-kg passenger car, by a 2000-kg pickup truck (2000P) under NCHRP Report 350 guidelines. The crash test reported herein was performed in an effort to evaluate a modified W-beam transition design (on steel posts with timber blockouts) to the vertical flared back concrete bridge parapet according to NCHRP Report 350 guidelines.|The crash test performed corresponded to NCHRP Report 350 test designation 3-11 involving a 2000P test vehicle impacting the transition at a nominal speed and angle of 100 km/h and 25 degrees. The transition contained and redirected the vehicle. However, the vehicle rolled over after exiting from the test installation. The modified W-beam transition (on steel posts with timber blockouts) to the vertical flared back concrete bridge parapet was therefore judged as not meeting the evaluation criteria set forth in NCHRP Report 350.