Guide Specifications for Bridges Carrying Light Rail Transit Loads
|Publication Date:||1 January 2018|
These guide specifications (LRT Guide Specifications) are a supplement to the AASHTO LRFD Bridge Design Specifications (LRFD Bridge Design) that address the design of bridges subjected to light rail transit (LRT) loadings, or both LRT and conventional highway traffic loadings. The LRT Guide Specifications state only the minimum requirements necessary to provide for public safety and are not intended to supplant proper training or the exercise of judgment by the Designer. The Owner or the Designer may require levels of sophistication for design and quality of materials and construction to be higher than the minimum requirements.
Except as superseded herein, LRFD Bridge Design and the AASHTO LRFD Bridge Construction Specifications shall govern the design and construction of bridges subjected to LRT loadings, or LRT and conventional highway loadings. Seismic design shall be in accordance with either the provisions in the appropriate sections of LRFD Bridge Design or the provisions in the AASHTO Guide Specifications for LRFD Seismic Bridge Design.
This document is largely dedicated to LRT load cases and load effects, and analysis of bridges subjected to LRT loadings. The following subjects are not covered: mechanical and electrical components of light rail trains, track materials and configurations, public utilities, transit signal work, and the maintenance of transit systems.
The commentary is not intended to provide a detailed summary of the studies and research data reviewed in formulating the provisions of the LRT Guide Specifications. However, technical discussions are provided as required.