Guidelines for the Development and Application of Crash Modification Factors (2022) / Chapter Skim
Currently Skimming:
Pages 335-338
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 335... ...
E-1 Contents E-1 Introduction E-1 Using the Tool E-2 Example Images Introduction The CMF Combination Tool is a Microsoft Excel spreadsheet implementation of the homogeneity testing procedure developed under NCHRP Project 17-63: Guidelines for the Development and Application of Crash Modification Factors. This tool can be used to test two or more CMFs for the same treatment to determine whether they are similar enough to be combined into a single CMF value.
|
From page 336... ...
E-2 Guidelines for the Development and Application of Crash Modification Factors The caution messages inform the user about certain conditions that might apply to the results. • Caution 1 alerts the user if the combined CMF is greater than 1.0, indicating that the treatment may cause an increase in crashes.
|
From page 337... ...
User Guide for the CMF Combination Tool Spreadsheet E-3 Figure E3. Example of two CMFs that should not be combined because the statistical variability was too large.
|
From page 338... ...
E-4 Guidelines for the Development and Application of Crash Modification Factors Figure E5. Example of two CMFs that have a combined result that should be used with caution for producing quantitative estimates of crash frequency reduction because the result may be statistically unreliable due to a large standard error.
|
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.