Refined Load Ratings, Automated with

Refined load ratings improve on traditional approximate (single line girder) methods by using a finite element model of a bridge to compute member demands. This model is not subject to assumed distribution factors, rather member demands are distributed within the models’ elements according to their stiffness and configuration. This approach produces a more accurate representation of complicated geometries, nontraditional bridges, or any other bridge where simplified live load distribution formulas are either not applicable, or result in a rating that is lower than acceptable. Our refined load rating effort focuses on a realistic simulation of a bridge’s response to various loading in order to compute a more accurate estimation of demands compared to traditional rating methods.

Intelligent Infrastructure Systems has experience in performing refined load ratings using LFR and LRFR methodologies according to the requirements of AASHTO Manual for Bridge Evaluation (MBE). Our use of finite element software leverages programming interfaces to automate model creation, analysis, results extraction, and load rating procedures to quickly and efficiently produce load ratings from what can be an otherwise tedious process. This in-house automation routine is called Bridgemiser.

Bridgemiser doesn’t replace engineering judgement or decision making, but it does make the process more efficient and repeatable. Best-practice analysis methods have been programmatically defined to enable quick and efficient implementation. The results from this automated routine can be presented interactively, across a complete structure for a more comprehensive understanding of the structure, and the analysis results. An example of this interactive result is presented below.

For more information about Bridgemiser or our Refined Load Rating services, please contact us at


Bridgemiser accommodates a variety of structural configurations


 Automation with Bridgemiser

Interactive Rating Results

(left mouse drag to rotate, right mouse drag to pan, scroll to zoom, hover for data, click legend items to toggle)