Michigan urban trunkline segments safety performance functions (SPFs) : final report.

Details

• Alternative Title:
  Michigan urban trunkline segments safety performance functions (SPFs) development and support.
• Creators:
  Savolainen, Peter T. ; Gates, Timothy ; Lord, Dominique ; Geedipally, Srinivas R. ; Rista, Emira ; Barrette, Timothy ; Thompson, Patricia ; Thompson, Iftin
• Corporate Creators:
  Michigan State University. Department of Civil and Environmental Engineering
• Corporate Contributors:
  Michigan. Dept. of Transportation. Research Administration ; United States. Federal Highway Administration
• Subject/TRT Terms:
  • Arterial highways
  • Crash data
  • Crash severity
  • High risk locations
  • Trend (Statistics) Safety performance function
  • segments
  • trunkline
  • crash modification factor
• Publication/ Report Number:
  RC-1639
• Resource Type:
  Tech Report
• Geographical Coverage:
  United States;Michigan
• Edition:
  Draft final report, 09/30/2013 - 09/30/2016
• Corporate Publisher:
  Michigan. Department of Transportation
• Abstract:
  This study involves the development of safety performance functions (SPFs) for urban and suburban trunkline segments in the ; state of Michigan. Extensive databases were developed through the integration of traffic crash information, traffic volumes, and ; roadway geometry information. After these data were assembled, an exploratory analysis of the data was conducted to identify ; general crash trends. This included an assessment of the base models provided in the Highway Safety Manual (HSM), as well as ; a calibration exercise, which demonstrated significant variability in terms of the goodness-of-fit of the HSM models across ; various site types. Michigan-specific SPFs were estimated, including simple statewide models that consider only annual average ; daily traffic (AADT), as well as regionalized models which take into account regional differences in traffic patterns and roadway ; geometry. More detailed models were also developed, which considered additional geometric factors such as lane width, right ; and left shoulder widths, median width, driveway density, on-street parking driveway density by land use, school count, posted ; speed limit, and intersection and crossover density. Crash modification factors (CMFs) were also estimated, which can be used to ; adjust the SPFs to account for differences related to these factors. Separate SPFs were estimated for two-way arterials and oneway ; arterials. Additionally, severity distribution functions (SDFs) were estimated, which can be used to predict the proportion of ; injury crashes experienced. The SDFs may include various geometric, operation, and traffic variables that will allow the ; estimated proportion to be specific to an individual segment. Ultimately, the results of this study provide MDOT with a number ; of methodological tools that will allow for proactive safety planning activities, including network screening and identification of ; high-risk sites. These tools have been calibrated such that they can be applied at either the statewide level or within any of ; MDOT’s seven geographic regions, providing additional flexibility to accommodate unique differences across the state. The ; report also documents procedures for maintaining and calibrating these SPFs over time, allowing for a consideration of general ; trends that are not directly reflected by the predictor variables.
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• Format:
  PDF
• Funding:
  2013-0066 Z6
• Download URL:
  https://rosap.ntl.bts.gov/view/dot/31461/dot_31461_DS1.pdf
• File Type:
  [PDF - 2.78 MB]
• Collection(s):
  US Transportation Collection
• Main Document Checksum:
  urn:sha-512:7979429cea42618b599b28f70053b9754e38e525206f5e5761d342a4b328e49a8dfb489617767d59f9e7017da004b0a420ef7533db9ab7e1d437583c5198480e