An Assessment of the

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An Assessment of the Operational Benefits of
Countdown Pedestrian Signals John R.
Engle Ghassan Abu-Lebdeh Thomas
Maleck Department of Civil and Environmental
Engineering Michigan State University
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Project Description

• 16 Intersections along MDOT State Trunklines
  within the State of Michigan
• 20 Hours of Data for Before and After Conditions
• Survey of Pedestrians

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What is a Countdown Pedestrian Signal (CPS)?
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What was discovered

• After implementation, majority of peds in the
  crosswalk (when Solid Dont Walk phase began)
  tended to be closer to curb.
• Being closer to their destination, the peds were
  able to leave the roadway quicker after the
  flashing dont walk phase ended.
• People overwhelmingly liked them.

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What was discovered

• There are significant exceptions to the
  generalizations made previously
• There were a significant number of intersections
  in which this did not occur
• Much of this variance could potentially be
  attributed to social/economic characteristics of
  the pedestrians

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• The 16 Intersections were broken down into three
  groups for analysis.

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Group A

• Michigan _at_ Larch - Lansing
• Saginaw _at_ Capitol - Lansing
• Saginaw _at_ Pennsylvania - Lansing
• Michigan _at_ Rose - Kalamazoo
• Bridge _at_ Jefferson - Grand Ledge
• Beach _at_ 5th - Flint

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Group A Findings

• Normal geometric layouts with peds exhibiting
  usual behavior
• After CPS, a small increase in volume of peds who
  cleared before solid dont walk (SDW) phase
• After CPS, minor decrease in the percentage of
  pedestrians crossing on the SDW phase

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• In five of the six locations of Group A, after
  CPS implementation a larger percentage of peds
  began crossing during flashing dont walk (FDW)
  phase
• With CPS, if peds were caught in the
  intersection when FDW phase ended, they tended to
  be much closer to their destination curb than
  before

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Saginaw/Capital Location - Lansing
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Saginaw/Capital Location - Lansing
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Group B

• Gratiot _at_ Linhurst - Detroit
• Gratiot _at_ Hickory - Detroit
• Gratiot _at_ Outer - Detroit
• Gratiot _at_ Filbert - Detroit
• Dexter _at_ Washington - Ionia
• Genesee _at_ Washington - Saginaw

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Group B Findings

• Locations in distressed, lower income
  neighborhoods
• Number of pedestrians that exhibited unusual
  walking behaviors was significantly higher than
  at other locations

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Group B Findings

• For five of the six locations, percentage of peds
  who cleared before the solid dont walk increased
  after CPS
• Percentage of peds crossing on SDW also decreased
  for five of the six locations

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Gratiot/Outer Location - Detroit
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Gratiot/Outer Location - Detroit
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Group C

• Mission _at_ Bellows - Mt Pleasant
• Michigan _at_ Ann Arbor - Saline
• Wyoming _at_ 8 Mile - Detroit
• VanDyke _at_ 10 Mile - Centerline

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Group C Findings

• Miscellaneous group
• No consistency between intersections
• Four intersections, locations w/ certain unique
  geometric layout, traffic flow, or pedestrian
  behavior may have resulted in different behavior
  problems

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Case Example Mt Pleasant

• Near CMU campus
• Majority of peds were college students, who
  displayed more aggressive walking behaviors
• Often would use countdown clock from another
  approach to decide
• This may explain the higher percentage of peds
  crossing on solid dont walk after the CPS

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Case Example Centerline

• Demographics similar Group A
• Unique geometric feature very wide highway width
  of VanDyke with no median (108 ft)
• After CPS a greater cleared before the solid
  dont walk
• Little change on bringing peds closer to curb
• Possible, CPS encouraged peds to walk faster
  compared to an unusually long flashing dont walk
  phase

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Case Example Detroit/8Mile

• Near a school
• Majority of peds middle school and elementary
  school children who crossed 8 Mile Road
• Majority of peds were unable to clear the
  intersection in one phase
• Resorted to waiting on a median island before
  completing their crossing

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Wyoming/8Mile Location - Detroit
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Case Example Detroit/8Mile

• Exception to majority of behaviors
• Located in a exurb of Ann Arbor
• Majority of peds high income demographic.
• Unclear why after CPS a lower of peds cleared
  before solid dont walk, or why

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Survey Results
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Survey Results
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Summary

• Impact was mostly positive
• There appear to be some exceptions
• Non-engineering factors important at some
• More analysis needed
• Statistical
• Qualitative
• Relevant finding to start develop guidelines

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Questions?