1. www.pathvu.com; Contact: Eric Sinagra, eric.sinagra@pathvu.com
America Walks
Learning Objectives
Sidewalk-related research leading to roughness standard
ASTM sidewalk roughness standard and suggested thresholds
Importance of technology and data
Future of data for accessibility
Jonathan Duvall, PhD student
Rehabilitation Sciences, University of Pittsburgh
Co-Founder, pathVu,
Contact: Eric Sinagra,

2. Health Motivation
WC users experience may have health consequences related to vibration
60% of WC users report neck pain & discomfort
Postural issues are common among WC users
Vibration Exposure Standards (ISO & 2631)
Provide measurement and analysis techniques
Provide exposure thresholds
Transfer and related studies have shown that wheelchair users have chronic pain. Also and ISO standard on whole-body-vibration health risks. Question: Can vibrations from using wheelchair cause this pain and discomfort?
The graph in the bottom left is pulled from the ISO standard. It depicts the health guidance caution zone. Each set of lines is a different equation, and anything above the lines is considered dangerous.

3. Related Research Roadloads (Van sickle ‘94,’96, ‘97, ’00,’04)
Developed instrumentation to measure reaction force at caster and propulsion wheels of MWC & recorded data in- lab and in-home & during wheelchair testing.
Seating System Influence (DiGiovine 2000 & 2003)
Influence of seating system on comfort and vibration exposure in-lab human trials
ICPI/BIA (Wolf, Cooper, Pearlman & 2007)
Influence of surface features on vibration exposure
Suspension (MWC: Kwarciak; PWC: Wolf, 2008)
Influence of suspension system on vibration exposure
Influence of Cushion (Pearlman, Garcia & Cooper, 2011)
Characterization of the WC cushion transmissibility
Community Vibrations (Pearlman, Garcia & Cooper, 2012)
Evaluation of MWC vibration exposure in the community
Pathway Roughness of Sidewalks (Pearlman, Duvall, Sinagra, 2013 & 2014)
Pathway Measurement Tool (Sinagra, Duvall, Pearlman, 2014)
Pathway Roughness Thresholds (Duvall, Pearlman, Cooper, 2016)
ASTM Pathway Roughness Standard (2016)
17 PUBLICATIONS ON THE TOPIC

4. Related Research Level of Vibrations Cushions Suspensions
Exposure is mostly within or above caution zone
Results insensitive to WC type
Cushions
Cushions often amplify vibrations into body (Garcia ‘12)
Are not selected such that they minimize vibration (DiGiovine ‘00)
Suspensions
Not optimized in manual (Kwarciak) or Power Wheelchairs (Wolf)
Sidewalk Characteristics
Vibration on newly installed segmental pavers depends on paver bevel and pattern
Some paver surfaces are smoother than poured concrete
17 PUBLICATIONS ON THE TOPIC

5. Outputs & Outcomes
Extrinsic Factors are determined by US Access Board based on ADA & ABA
Current Guidelines
Running slope (1:20)
Cross-slope (1:50)
Level Changes (1/4”)
Stable, firm, & Slip Resistant
Roughness?

6. Simulated & Community
1.6
Mali Flag….
© 2014, Jon Pearlman

7. Threshold Options Vibration Results Survey Results
1.6
Vibration Results
Exposure Time 
2 hr
1 hr
30 min
< 10 min
Health Guidance Zone Boundary
Low
High
RMS Limit (m/s2)
0.7
1.6
0.85
2.5
1.1
3.5 6
All surfaces, All Chairs
0.29
0.65
0.35
1.02
0.45
1.42
2.43
All Surfaces, Manual Chairs
0.21
0.49
0.26
0.76
0.33
1.07
1.83
Engineered Surfaces, Manual Chairs
0.17
0.48
0.22
0.79
0.31
1.13
1.98
Survey Results
Data
% Acceptable
Rating
Criteria
75%
50%
"good" (3.5)
"fair" (2.5)
All surfaces, All chairs
0.75
1.19
0.59
1.14
All surfaces, Manual chairs
0.72
1.16
0.62
1.18
All surfaces, Power chairs
0.79
1.23
0.56
1.12
Engineered Surfaces, Manual Chairs
0.74
1.24
0.63
Engineered Surfaces, Power Chairs
0.68
0.46
1.00
Thresholds: 0.6 in/ft and 1.2 in/ft

8. 0.39
Acceptable

9. marginal

11. ASTM Standard
Standard Practice for Computing Wheelchair Pathway Roughness Index related to User comfort, acceptance and Whole body vibrations from longitudinal profile measurements
ASTM
Reviewed by ASTM subcommittee
Accessible at:
$45 fee

12. Suggested Thresholds
Proposed pedestrian pathway roughness thresholds to ensure safety and comfort for wheelchair users
Journal of Assistive Technology. The Official Journal of RESNA. Volume 28, Issue 4.
Accessible at:
Thresholds
50.0 mm/m (0.60 in/ft)
100.0 mm/m (1.20 in/ft)

13. Tools Developed as part of the work: PathMeT (www.pathvu.com/pathmet)B C D
ICPI/BIA funding was use to develop community-ready data collection tool
A) Funded by US Access Board
B,C) Funded by ICPI/BIA support
D) Funded by pathVu

14. Output Measurements WPRI Roughness Lippage/Step Height Running Slope
Cross Slope
Depressions (Pot Holes)
Location (GPS)
Images (Every 10 ft)

15. pathVu app
PathMeT

16. Sidewalk Mapping

18. Visualization

20. Future
Public Rights of Way Accessibility Guidelines (PROWAG): Coming in 2017
National database of sidewalks
Accessible navigation directions

21. Contact: Eric Sinagra, eric.sinagra@pathvu.com
Thank you!
Contact: Eric Sinagra,

22. Publications & Standards related to Sidewalk Roughness
Pedestrian Pathway Characteristics and Their Implications on Wheelchair Users. Jonathan Pearlman PhD, Rory Cooper PhD, Jonathan Duvall BS & Ryan Livingston (2013), Assistive Technology: The Official Journal of RESNA.
Development of Surface Roughness Standards for Pathways Used by Wheelchairs Duvall J., Cooper R. A., Sinagra E., Stuckey D., Brown J., Pearlman J. , (2013), Transportation Research Record , no. 2387, pp
Proposed Pedestrian Pathway Roughness Thresholds to ensure safety and comfort for Wheelchair Users. Duvall, J. Sinagra, E., Cooper, R., J. Pearlman (2016), Assistive Technology: The official Journal of RESNA. Accessible at:
Standard Practice for Computing Wheelchair Pathway Roughness Index related to User comfort, acceptance and Whole body vibrations from longitudinal profile measurements. Accessible at: