Details:

Creators:
Abdel-Aty, Mohamed A. ; Lee, Chris ; Park, Juneyoung ; Wang, Jung-Han ; Abuzwidah, Muamer ; ... More +
Abdel-Aty, Mohamed A. ; Lee, Chris ; Park, Juneyoung ; Wang, Jung-Han ; Abuzwidah, Muamer ; Al-Arifi, Saif Less -
Corporate Creators:
University of Central Florida. Dept. of Civil, Environmental and Construction Engineering
Subject/TRT Terms:
[+]
Accident Data Before And After Studies Countermeasures Highway Safety Manuals Traffic Accidents Validation
Publication/ Report Number:
BDK78-977-14
Resource Type:
Tech Report
Geographical Coverage:
Florida
Corporate Publisher:
Florida. Dept. of Transportation
Abstract:
The Highway Safety Manual (HSM) Part D provides a comprehensive list of the effects of safety

treatments (countermeasures). These effects are quantified by crash modification factors (CMF), which are based

on compilation from past studies of the effects of various safety treatments. The HSM Part D provides CMFs for

treatments applied to roadway segments (e.g., roadside elements, alignment, signs, rumble strips, etc.),

intersections (e.g., control), interchanges, special facilities (e.g., highway-rail crossings), and road networks.

Thus, an assessment of the applicability of the HSM in Florida is essential. The objectives of this study are (1) to

develop CMFs for various treatments in Florida for the same setting (rural/urban), road type, crash type, and

severity level, (2) to evaluate the difference between these Florida-specific CMFs and the CMFs in the HSM, and

(3) to recommend whether the CMFs in the HSM can be applied to Florida or new Florida-specific CMFs are

needed. Different methods of observational study – before-after (B-A) and cross-sectional (C-S) – were used to

calculate CMFs for a total of 17 treatments applied to roadway segments, intersections and special facilities. The

CMFs calculated using the before-after with comparison-group (C-G) and empirical Bayesian (EB) methods,

only the CMF with lower standard error was selected. The methods of calculating CMFs were determined based

on the availability of the data and the methods used in the HSM, if the CMFs were provided in the HSM. It was

found that Florida-specific CMFs were generally statistically significant, and safety effects represented by the

CMFs were intuitive, similar to the CMFs in the HSM. It was also found that Florida-specific CMFs for the

treatments not included in the HSM showed significant positive effects in reducing crash frequencies.


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:d048a5f77ffd963a0d766a7a265e2870bf43ea6fcef3200bc62e04ea12088f5d
Download URL:
https://rosap.ntl.bts.gov/view/dot/27272/dot_27272_DS1.pdf
File Type:

Supporting Files

• No Additional Files

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