Title

High-Performance Aesthetic Bridge Rail and Median Barrier

Document Type

Journal Article

Publication Date

2009

Subject Area

operations - performance, infrastructure - vehicle, planning - safety/accidents, organisation - performance, mode - rail

Keywords

Safety performance, NCHRP Report 350, Median barriers, Impact tests, High performance concrete, Heavy vehicles, Esthetics, Economic factors, Design, Crash tests, Concrete barriers, Collision tests, Bridge rails, Bridge railings, Aesthetics

Abstract

Design of high-performance concrete barriers for heavy vehicles has advanced little in recent years. Barrier improvements were needed in terms of design aesthetics, safety performance, and economy. Advancement was deemed necessary for improved barrier geometry design to reduce vehicle instability and the potential for occupant head slap on the barrier, improved understanding of impact loads for heavy vehicles and use of these loads to optimize barriers, and improved barrier aesthetics. This paper describes the development of two NCHRP Report 350 Test Level 5 (TL-5) barriers that address these needed advancements. First, a TL-5 open concrete bridge rail was designed with a focus on determining accurate impact loads and providing a barrier geometry with improved safety and aesthetics. Next, a TL-5 concrete median barrier was developed through rigorous analysis of barrier shape options to determine the safest and most economic shape. Structural design of the barrier was also optimized to minimize cost while meeting the design loads for heavy vehicles. The open concrete bridge rail and the concrete median barrier were successfully full-scale crash-tested according to the TL-5 safety requirements set forth in NCHRP Report 350. These designs represent a major advancement in the safety and economy of high-performance concrete barriers.