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Federal Highway Administration Research and Technology
Coordinating, Developing, and Delivering Highway Transportation Innovations

Report
This report is an archived publication and may contain dated technical, contact, and link information
Publication Number: FHWA-RD-97-106

Rural Public Transportation Technologies: User Needs and Applications FR1-798

APPENDIX D

ACCIDENT FREQUENCY DISTRIBUTIONS FOR SELECTED INTERCHANGE ELEMENTS

This appendix presents a series of accident distribution plots for camp segmens, ramps, speed-change lanes, and combinations thereof. These include:

  • Ramp proper segments, off-ramps only (rear-end accidents exluded from frequency distributions) in figure 9.
  • Speed-change lanes (total and fatal and injury multiple-vehicle accidents) in figure 11.
  • Entire ramps, off-ramps only (rear-end accidnets excluded from frequency distributions) figure 10.
  • Entire ramps plus adjacent speed-change lane (total and fatal and injury multiple-vehicle accidents) in figure 12.
  • Urban diamond off-ramps (total and fatal and injury multiple-vehicle accidents) in figure 13.
  • Urban parclo and free-flow loops off-ramps (total and fatal and injury multiple-vehicle accidents) in figure 14.
  • Urban outer connection off-ramps (total and fatal and injury multiple-vehicle accidents) in figure 15.

In addition, 1-year accident (total and fatal and injury multiple-vehicle accidents) for the 551 entire ramps and the 737 ramp proper segments studied in this report are presented in figures 16 and 17, respectively, comparing the 3 years of accident data for 1993 through 1995.

Figure 9. Accident Frequency Distribution for Ramp Proper Segments, Off-Ramps Only (Rear-End Accident Excluded)

Figure 10. Accident Frequency Distribution for Entire Ramps, Off-Ramps Only-Ramps Only (Rear-End Accidents Excluded)

Figure 11. Accident Frequency Distibutions for Speed-Change Lanes

Figure 12. Accident Frequency Distributions for Entire Ramps, Including the Adjacent Speed-Change Lane

Figure 13. Accident Frequency Distributions for Urban Diamond Off-Ramps

Figure 14. Accident Frequency Distributions for Urban Parclo and Free-Flow Loop Off-Ramps

Figure 15. Accident Frequency Distributions for Urban Outer Connection Off-Ramps

Figure 16. Annual Accident Frequency Distributions for Entire Ramps (1993-1995)

Figure 17. Annual Accident Frequency Distributions for Ramp Proper Segments (1993-1995)

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