Roadside Design Guide


Book Description

This document presents a synthesis of current information and operating practices related to roadside safety and is developed in metric units. The roadside is defined as that area beyond the traveled way (driving lanes) and the shoulder (if any) of the roadway itself. The focus of this guide is on safety treatments that minimize the likelihood of serious injuries when a driver runs off the road. This guide replaces the 1989 AASHTO "Roadside Design Guide."







Guardrail Performance and Design


Book Description

Barrier installations are warranted (or justified) only at highway locations where the consequence of an errant vehicle leaving the roadway is judged to be more hazardous than the impact with the barrier installation. A six degree-of-freedom mathematical model was found to be useful in describing dynamic behavior of a vehicle during impact. Predictions of vehicle and barrier behavior correlated with results obtained from full-scale crash tests. Crash conditions simulated with a computer were used to identify and evaluate vehicle static and dynamic as well as barrier parameters. Vehicle weight, yaw mass moment of inertia, and deformation constant were found to be significant.







NCHRP Report 537


Book Description




Testing and Evaluation of the W-beam Transition (on Steel Posts with Timber Blockouts) to the Vertical Flared Back Concrete Bridge Parapet


Book Description

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.







Roadside Design Guide


Book Description

"The Roadside Design Guide presents a synthesis of current information and operating practices related to roadside safety and is written in dual units-metric and U.S. Customary. This book is a guide. It is not a standard, nor is it a design policy. It is intended to use as a resource document from which individual highway agencies can develop standards and policies. Although much of the material in the guide can be considered universal in its application, several recommendations are subjective in nature and may need modification to fit local conditions. However, it is important that significant deviations from the guide be based on operational experience and objective analysis. The 2011 edition of the AASHTO Roadside Design Guide has been updated to include hardware that has met the evaluation criteria contained in the National Cooperative Highway Research Program (NCHRP) Report 350: Recommended Procedures for the Safety Performance Evaluation of Highway Features and begins to detail the most current evaluation criteria contained under the Manual for Assessing Safety Hardware, 2009 (MASH). For the most part, roadside hardware tested and accepted under older guidelines that are no longer applicable has not been excluded in this edition." -- AASHTO website.