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Guidelines for Selection of Speed Reduction Treatments at High-Speed Intersections (2008) / Chapter Skim
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Appendix C - Testing Results
Pages 95-97

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From page 95...
... • Of the 51 before-and-after speed comparisons, 34 were statistically significant. C.2 Analysis by Intersection Approach An analysis by intersection approach was conducted to determine the overall speed reduction observed along an intersection approach as a result of the treatment installed on that approach.
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From page 96...
... Key findings include the following: • Dynamic warning signs were the only treatment to have a statistically significant overall effect at the 5% significance level in reducing mean speeds from before to after installation, with a mean speed reduction of 1.7 mph. • Transverse pavement markings had a statistically significant overall effect at the 10% significance level in reducing mean speeds from before to after installation, with a mean speed reduction of 0.6 mph.
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From page 97...
... • Based on a limited number of sites, rumble strips do not appear to be as effective at reducing speeds as dynamic warning signs or transverse pavement markings. Testing Results 97
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Key Terms

  • warning signs
  • speed reduction
  • intersection approaches
  • mean speed
  • intersection approach

  • transverse pavement
  • reducing mean
  • mean speeds
  • pavement markings
  • treatment types

  • reduction observed
  • speed location
  • significant overall
  • overall effect
  • rumble strips

  • speed reductions
  • reducing speeds
  • overall speed
  • estimated speed
  • significance level

  • speed difference
  • installed experienced
  • cance level
  • estimated mean
  • fourteen intersection

  • reduce speeds
  • treatment installed
  • signs resulted
  • reduction treatments
  • collection location


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