Overview of Drawings and Specifications
This Guide contains drawings and specifications for barrier systems and their components. Each system and component has been assigned a unique designator, such as SGR01a. Those that appeared in earlier versions of the Guide retain their previous designator. Some of the details shown in this Guide have been revised from earlier details to conform to the most current hardware. Every effort has been made to assure the correctness of the drawings and specifications at the time of publication, but a designer wishing to use details in this Guide should assure themselves of the geometric and structural adequacy of the design. Citations to the roadside safety literature have been provided so that the designer may search out the test results and become familiar with the development of each barrier system.
The drawings for the components and systems in this Guide were produced using AutoCAD, Microstation, or other software and converted to PDF for ease of viewing and downloading. Similarly, the text specifications were produced using Word, WordPerfect, or other software and converted to PDF. The drawing and specification standards for the Guide are available on this website.
Units
Dimensions in the drawings are given in both inches and millimeters, with the millimeter measurement in brackets. For example, a height of 30 inches (762 millimeters) is labeled as 30 [760]. In general, unit conversions and rounding conform to the recommendations of AASHTO R1-91.
Abbreviations
The following abbreviations are used in the drawings:
| CLR | clear distance |
| D | diameter |
| EA | each |
| OC | on-center |
| LONGIT | longitudinal reinforcement |
| LNG | long |
| MAX | maximum |
| R | radius |
| TOL | tolerance |
| TYP | typical |
The following abbreviations are used in the specifications for standards-making organizations:
| AASHTO | American Association of State Highway and Transportation Officials |
| AISC | American Institute of Steel Construction |
| AGC | Associated General Contractors |
| ANSI | American National Standards Institute |
| ARTBA | American Road and Transportation Builders Association |
| ASTM | American Society for Testing and Materials |
| AWS | American Welding Society |
| FHWA | Federal Highway Administration |
| IFI | Industrial Fasteners Institute |
| SAE | Society of Automotive Engineers |
There is a great deal of intentional duplication between the AASHTO and ASTM material specifications; generally, the AASHTO version of a specification is considered the primary reference and the ASTM reference is included in parentheses for the convenience of the user. Both English and metric specifications are cited in this Guide, with the metric specification enclosed in brackets (e.g., AASHTO M183[M183M](ASTM A36[A36M])).