Improving Motor Carrier Safety Measurement (2017) / Chapter Skim
Currently Skimming:
Summary
Summary
Pages 1-10
The Chapter Skim interface presents what we've algorithmically identified as the most significant single chunk of text within every page in the chapter.
Select key terms on the right to highlight them within pages of the chapter.
From page 1... ...
To help ensure a high standard of safety, the Federal Motor Carrier Safety Administration (FMCSA) , with its mission "to reduce crashes, injuries and fatalities involving large trucks and buses," makes use of the Compliance, Safety, and Accountability Program, and, in particular, the Safety Measurement System (SMS)
|
From page 2... ...
Two units in the National Academies -- the Committee on National Statistics in collaboration with the Transportation Research Board -- began work in March 2016, convening the Panel on the Review of the Compliance, Safety, and Accountability Program of the Federal Motor Carrier Safety Administration for this congressionally mandated study. The panel was charged with analyzing the ability of SMS measures to discriminate between low- and high-risk carriers, assess the public usage of SMS, review the data and methodology used to calculate the measures, and provide advice on additional data collection and safety assessment methodologies.
|
From page 3... ...
Given that, and the relative rarity of crashes for small carriers, the panel agrees that development of a crash prediction model based on carrier-level behavior using MCMIS data is not a productive way to approach the problem of discrimination between safe and unsafe commercial motor carriers. With SMS, FMCSA has instead adopted a sensible, related approach based on prevention rather than prediction.
|
From page 4... ...
Specifically, IRT models would have the following specific advantages over SMS: • nstead of severity weights being based on expert opinion or I dated empirical information, the item discrimination parameters are estimated based on a combination of current observed data and expert opinion, and ultimately on data alone. • RT models can enhance the transparency of the evaluation I system.
|
From page 5... ...
. Two specific data elements require immediate attention: carrier exposure and crash data.
|
From page 6... ...
To address these issues, FMCSA should support the states in collecting more complete crash data, and in universal adoption of the Model Minimum Uniform Crash Criteria, as well as developing and supplying the code needed to automati cally extract the data needed for the MCMIS crash file. Improvement through Additional Variables and Possible New Sources The information available on MCMIS is limited in terms of the ability to determine the factors that contributed to a crash.
|
From page 7... ...
TRANSPARENCY, REPRODUCIBILITY, AND PUBLIC DISCLOSURE OF SAFETY RANKINGS SMS percentile ranks have very important implications for CMV carriers. Hence, it would be useful if the CMV community were able to reproduce the SMS measures and percentile ranks, that researchers have
|
From page 8... ...
Given this, we make the following recommendation: RECOMMENDATION: The Federal Motor Carrier Safety Adminis tration should undertake a study to better understand the statistical operating characteristics of the percentile ranks to support deci sions regarding the usability of public scores. SMS percentile ranks are a relative metric, and so a motor carrier's efforts toward improving its safety performance will not be reflected in the percentile ranks if other carriers in its peer group have improved even more.
|
From page 9... ...
alerts using both the SMS percentile ranks and the SMS measures, and the percentile ranks should be computed both conditionally within safety event groups and over all motor carriers.
|
Key Terms
This material may be derived from roughly machine-read images, and so is provided only to facilitate research.
More
information on Chapter Skim is available.