Transportation Research Board (TRB) 91st Annual Meeting Washington, D.C., January 22-26, 2012

1. Making Bellevue’s Sidewalks Accessible for Everyone
TRB 2012 Annual Meeting Paper: 12-1439
Franz Loewenherz
Senior Transportation Planner
City of Bellevue (WA)

2. ADA Culture of Compliance

3. Americans with Disabilities Act (ADA)
Title II – Government Services: Must ensure that individuals
with disabilities are not excluded from programs, services, and
activities (pedestrian facilities are an example of a program).

4. Title II Elements

5. Bellevue ADA Sidewalk & Curb Ramp
Self Evaluation

6. Sidewalk & Curb Ramp Inventory Overview
Top Landing Moveable Obstruction
Absence of level landing Tactile Warning
Fixed Obstruction
Heaving
Ramp cross slope
Bottom Landing
No Ramp Ramp Transition

7. Guidance for Conducting an ADA Inventory
FHWA (1999) PROWAAC (2007) Texas DOT Maryland Highway
AASHTO (2004) NCHRP (2008) City of Sacramento Florida DOT
Reference reports Inventory tools

8. Bellevue’s Approach
1 2 3
Data Collection Database Analysis Barrier Ranking
Disability Community Participation

9. Data Collection

10. ADA Curb Ramp Inventory

11. ADA Sidewalk Inventory
On January 22, 2004, in the case of Barden v. Sacramento, the 9th
Circuit Court ruled that sidewalks were a "program" under ADA and
must be made accessible to persons with disabilities.
Running Slope Cross Slope Displacement Protrusions Obstructions
1:20 (5%) max 1:50 (2%) max 1/4 inch max 4” max (27” - 80”) 36” clear width
ADAAG 4.8 ADAAG 4.3.7 ADDAG 4.5.2 ADDAG 4.4 ADDAG 4.3.3
FHWA guidance on grade and cross-slope:
“should be measured over 2 ft intervals, the approximate
length of a wheelchair wheelbase, or a single walking pace.”

12. Technology Development Partnership
Project assessed
the applicability of
inertial profiling
technologies in
identifying existing
sidewalk and ramp
facilities that limit
access for persons
with disabilities.
Coordinated staffing & funding commitment from
three agencies from three levels of government.

13. ULIP Technology
Sensor box includes:
1. a displacement laser
(texture/profile/height),
2. three accelerometers (inertial
profiling),
3. a gyroscope (pitch, roll, yaw),
4. optical trigger (reference),
5. GPS (general location), and
6. a DMI (travel distance system).
Computer and data acquisition card
are used for data capture.

14. ULIP Data Transfer
Data Capture Data Acquisition
GIS Integration Data Processing

15. Quality Assurance/Quality Control

16. Attribute Accuracy of Data
Field technicians check the slope and grade of sidewalk
segment with smart level for QAQC validation of ULIP data.
Cross Slope Running Slope Data Acquisition

17. Validation Report: Smart Level/ULIP
Cross Slope Data Verification
10
8
Cross Slope %
6 Smart Level Reading
ULIP Survey
4
ADAAG Compliance
2
0
0
8
16
24
32
40
48
56
64
Distance (ft.)
 ULIP data consistently Running Slope Data Verification
follows with the Smart 14
Level’s peaks and 12
Running Slope%
10
Smart Level Reading
troughs at test sites. 8
ULIP Survey
6
ADAAG Compliance
4
 Rise versus Running 2
Distance compared to 0
0
8
16
24
32
40
48
56
64
ADAAG. Distance (ft)

18. ULIP Path Repeatability for Grade
ULIP Grade (4 runs) vs Smart Level
9
8
7
1024
6 1026
1027
Grade %
5 1028
SL
4
3
2
1
0
80 100 120 140 160 180 200
Feet

19. ULIP Path Repeatability for Cross Slope
ULIP Cross Slope (4 Runs) vs Smart Level
4
3.5
3
Cross Slope %
2.5
2
1.5
1024
1 1026
1027
1028
0.5
SL
0
80 100 120 140 160 180 200
Feet
Site was a sidewalk with two successive driveway crossings.

20. Change in Level Output Reports
Field Validation Mode ASCII text file Data in City’s GIS
QA/QC

21. Positional Accuracy of Data
Streaming GPS Sensor-based inertial navigation
Bellevue testing with global Start/end points for each data
navigation satellite system collection run entered on an
(GPS) found the accuracy of ortho-photo image on the ULIP’s
latitude/longitude data degraded notebook computer screen. The
in areas with tall buildings or gyroscope and distance
thick tree canopies. measurement instrument were
used to compute path of travel.

22. Roadway Grade Analysis

23. Measurement of Grade
Maximum grade is defined as a limited section of path that
exceeds the typical running grade.

24. Raw Data Allows for Infinite Re-analysis
Averaging Window SIze Effect on Grade (%)
9
1G
8
2G
7 3G
4G
6 5G
10 G
5 20 G
30 G
4
Grade %
40 G
50 G
3
2
1
0
1325 1330 1335 1340 1345 1350 1355 1360 1365 1370 1375
-1
-2
-3
Distance (Feet)
Grade and Cross Slope Averaging Window Size:
• In the ULIP Geometry Equation, the user specifies the grade and cross
slope window size in feet to be applied in a moving average computation.
• The graph illustrates the effect of moving average window size. The larger
the value, the more dampened out the features.

25. User-Specified Window Size
FHWA guidance on grade and cross-slope:
“should be measured over 2 ft intervals, the approximate
length of a wheelchair wheelbase, or a single walking pace.”
Original profile
Current position
Smoothed profile
Average height
of shaded area
B

26. Grade Compliance Criteria
An accessible route with a running slope greater than 1:20 (5%)
is a ramp and shall comply with ADAAG 4.8. (ADAAG 4.3.7)
level surface of
landing ramp
 Maximum slope 8.33%
level  Maximum rise for any run shall be 30”
landing  Minimum clear width shall be 36”
 Level landings at bottom and top of
30” max.
horizontal projection each ramp
rise
or run
Slope Maximum Rise (inches) Construction Type
1:20 to 1:16 (5% to 6.3%) 30 New const. & modifications
1:16 to 1:12 (6.3% to 8.3%) 30 New const. & modifications
1:12 to 1:10 (8.3% to 10%) 6 Modifications only
1:10 to 1:8 (10%- 12.5%) 3 Modifications only

27. Running Slope Analysis
Allow sidewalk running slope
to match roadway grade.
- PROWAG (not ADAAG) Digital Elevation Model
 134 miles of our sidewalk facilities exceed 5% grade standard.
 95 miles are attributable to the adjacency of the roadway grade.
 39 miles of non-standard grade sidewalk surfaces are referenced
in the City’s Transition Plan document.

28. Digital Elevation Model Calculation
134 miles

29. Digital Elevation Model Calculation
134 miles
95 miles

30. Digital Elevation Model Calculation
134 miles
95 miles
39 miles

31. Driveway Cross Slope Analysis

32. Driveway Standards
Slope down at (8.3%)
1:12
2% cross-slope
Apron, may be any
acceptable grade
Slope
up at
1:12 (8.3%)
 Certain grades and slopes must be maintained.
 2% cross-slope,
 8.33% max ramp slopes if used.

33. Bellevue Design Manual
Bellevue employs a number of accessible driveway designs to maintain an
acceptable cross slope and facilitate wheelchair movement at driveways.
As reflected in DEV-7D above, securing additional right-of-way from the
adjacent property is a good strategy for improving pedestrian access on
narrow sidewalks. This design allows pedestrians to maintain a level path
as they cross the driveway.

34. Project Approach
Driveway crossings without landings confront wheelchair users with
severe and rapidly changing slopes at the driveway flare.
A series of driveway apron flares The driveway analysis is based on ULIP
with 11% cross slope recordings taken by field staff at the center
measurements at 130th Avenue points of driveways. Using GIS, any non-
SE & SE 26th Street. standard cross slope values within buffer are
attributed to the driveway aprons.

35. Cross Slope Findings
1. Over 50% of Bellevue’s 8+ percent cross slope measurements are
attributable to driveway aprons.
2. Number increases as cross slope values increase, with 70% of 10+
percent cross slope measurements attributable to driveway aprons.
3. Overall, 19% of all non-standard cross slope measurements are
attributable to driveway aprons constructed like ramps, with steep,
short side flares.

36. ADA Viewer Interface

37. Identify/ Print
ADA Viewer Window Navigation Extents Locate by
Toggle Bar Navigation Address
Legend/
Layers
Location
Map

40. Barrier Ranking Analysis

41. Compliance vs. Accessibility
ADA tells us which features are non-standard …
... But it doesn’t tell us which of these non-standard
features should be replaced first.

42. Community Outreach
Engaged people with disabilities to ensure to that we
fully understood their challenges and priorities.
 December 2007: 3 Focus Groups
 April 2009: Field tour in partnership with King County
 May 2009: ADA Accessibility Open House
 June 2009: Written survey with more than 100 responses
Poster at Open House Mail-Back Survey Ramp Assessments

43. Barrier Ranking Analysis
Land
Use Ramps
Streets Paths
Census Islands
Activity Impedance Barrier
Score Score Ranking

44. Legend

45. Legend

46. Legend

47. For More Information
The ADA Sidewalk and Curb Ramp Self-Evaluation Report is
located at: http://www.bellevuewa.gov/accessibility-reports.htm
“Efforts such as those at the City of
Bellevue, Washington, that rely on the
collection of large datasets at extremely
fine spatial and temporal disaggregation
levels have the potential to significantly
automate the identification of non-
compliant locations in the field.”
NCHRP 20-07 Task 249
- Texas Transportation Institute

48. Thank you
Franz Loewenherz
Senior Transportation Planner
City of Bellevue
450 110th Ave. NE
Bellevue, WA 98009
floewenherz@bellevuewa.gov
Phone: 425.452.4077