Details:

Creators:
Alluri, Priyanka ; Saha, Dibakar ; Liu, Kaiyu ; Gan, Albert
Alluri, Priyanka ; Saha, Dibakar ; Liu, Kaiyu ; Gan, Albert Less -
Corporate Creators:
Florida International University. Lehman Center for Transportation Research
Subject/TRT Terms:
[+]
Accident Data Calibration Data Collection Highway Safety Implementation Manuals Software Unsignalized Intersections
Publication/ Report Number:
BDK80-977-37
Resource Type:
Tech Report
Geographical Coverage:
Florida
Corporate Publisher:
Florida. Dept. of Transportation. Research Center
Abstract:
Recent research in highway safety has focused on the more advanced and statistically proven techniques of highway

safety analysis. This project focuses on the two most recent safety analysis tools, the Highway Safety Manual (HSM)

and SafetyAnalyst. Meeting the data requirements is considered the most challenging task in implementing these

tools.

In the case of HSM, many of the data variables needed for deriving the HSM calibration factors are currently

unavailable in Florida’s roadway characteristics inventory (RCI) database. This project attempts to identify and

prioritize influential calibration variables for data collection and to determine the minimum sample sizes to estimate

reliable calibration factors. For each facility type included in the HSM, this project applied the random forest

technique to rank both the required and desired variables based on their importance. The variables were categorized

into three groups: variables of primary importance; variables of secondary importance; and variables of lesser

importance. The minimum sample sizes to estimate reliable calibration factors for different facility types were also

determined. It was found that the minimum sample size of 30-50 sites with at least 100 crashes per year, as

recommended by HSM, is insufficient to achieve the desired accuracy for nearly all facility types.

Compared to HSM, SafetyAnalyst has lesser but different data requirements. Two major efforts in applying

SafetyAnalyst involve the conversion of local data into the strict data format required by SafetyAnalyst and the

development of jurisdiction-specific safety performance functions (SPFs). This project developed a software

program to convert the crash and roadway data for Florida’s state roads to “import” files used by SafetyAnalyst. In

addition, this project also developed the SPFs for unsignalized intersections to supplement those of other facilities

which were developed under a separate project. For demonstration, SafetyAnalyst was applied using Florida’s data to

identify high crash locations. Recommendations for deploying SafetyAnalyst are also provided.


Format:
PDF
Collection(s):
US Transportation Collection
Main Document Checksum:
[+]
urn:sha256:52bd521342c3132e4983180620840bc2f84ae7f322797d2ce0b6933e788e81a3
Download URL:
https://rosap.ntl.bts.gov/view/dot/27226/dot_27226_DS1.pdf
File Type:

Supporting Files

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