EFFECTIVENESS OF PEDESTRIAN SAFETY TREATMENTS FOR

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• EFFECTIVENESS OF PEDESTRIAN SAFETY TREATMENTS FOR
  
• HIT-ALONG-ROADWAY CRASHES

Chandler Duncan University of Minnesota Asad J.
Khattak Department of City and Regional
Planning University of North Carolina-Chapel
Hill Ronald Hughes Highway Safety Information
Center University of North Carolina-Chapel Hill
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Goals

• Examine crashes where pedestrians were
  hit-along-roadway segments
• Identify appropriate countermeasure strategies
  suggested by experts
• Draw implications from analysis
• US DOT funded field project
• HSRC implementer and evaluator

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WakeCounty
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WakeCounty
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Previous work literature

• Risk factors
• Higher speed limit, lack of wide grassy walkable
  areas, sidewalk absence
• Nbds. with high levels of unemployment, older
  housing stock, more single parents, higher uses
  of bus service for work commutes
• Different types of exposure
• Little focus on hit-along-roadway crashes
• Paucity of detailed crash inventory data
• Few attempts to explore countermeasures
• Applying expert opinions on complex phenomena

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Method
Objective Explore risk factors associated with
hit-along roadway crashes countermeasures

• Experimental Design data collection
• NC Wake County sites Extensive data collection
• Crash site (N47) 2 comparison sitesCompanion
  Remote
• Archived data Visit sites, take photos
  ped/veh counts
• Surveys for a diverse Delphi panel Two
  iterations

• Concepts
• Crash non-crash sites Dangerous
  not-dangerous?
• Risk f(Roadway/env factors Driver/ped
  vehicle)
• Correctly identified sites
• Countermeasures Infrastructure-based

• Analysis
• Can experts distinguish between crash and
  non-crash sites?
• Use panel responses to identify risk factors
• Panels opinion about countermeasures

• Conclusions and recommendations
• Visible risks countermeasures where subjective
  judgment objective outcomes agree?
• Implications

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Pictures for the Experts
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Delphi

• Panel of five HSRC ped safety expertsselected
  based experience and convenience
• Backgrounds in Psych, Bio-stats, Plan Eng
• 1st Iteration. Comparing triplets in terms of
• Least safe, pinpoint the visible risk factor
• Give relative importance of each risk factor
• Recommend countermeasures to offset the risk
• 2nd Iteration.
• Re-examine each triplet traffic and ped vol
• Information about others judgments
• Re-evaluate

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Expert Survey 1
Safest A
Risks at safest
Risks at least safe
Countermeasures
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Expert Survey 2
Volumes
Iteration 1 results Change in rankings
Importance of risk factors
Countermeasures
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TheoryRoad/env factors Driver/Ped, Vehicle
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Results Crashes opinions
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Risks
Crash identified coefficient of times when
risk X was mentioned, the site was crash site
(0-to-1) Risk importance Rating given to risk
X (0-to-1)
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What are the perceived risk factors?

• Discontinuous sidewalks
• Ambiguity about where peds should walk
• No unpaved walkable space
• No curb
• Road construction
• Cross traffic
• High vehicular volume
• Presence of large trucks

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What are the countermeasures recommended by the
panel?

• Specific countermeasures sensitive to what seemed
  'most appropriate' or 'likely to be installed'
  given urban or rural nature of env.
• Widen unpaved shoulder
• Construct pathway/walkway
• Install a sidewalk
• Install street lighting
• Effective lateral separation between motorized
  non-motorized traffic

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Matching risks countermeasures
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Limitations

• Contribution of driver/ped vehicle factors not
  investigated, e.g.,
• Drunk driver/ped
• Large truck
• Obtaining additional field data difficult
• Nighttime crashes
• Neighborhoods

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Conclusions

• Pinpointing key risk factors countermeasures
• Lateral separation (sidewalk paved shoulders)
  encouraged
• May not be a universal measurescost
• Where are they needed?
• High-risk locations identified

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Implications

• Experts limitations in pointing risks
• Infrastructure/env hazards may not always be
  obvious
• Delphi method to arrive at consensus on risks
  and countermeasures
• Valuable method

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Future Steps

• Explore methods that can enhance lateral
  separation of vehicles and peds
• Travel lane boundary reflectors
• Rumble strips