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Trb paper 12 1439 (11-23-12)

Franz Loewenherz
Franz Loewenherz

The City of Bellevue conducted an inventory of its sidewalks and curb ramps to evaluate accessibility for people with disabilities, as required by the Americans with Disabilities Act (ADA). The city used an Ultra Light Inertial Profiler to collect detailed data on sidewalk grades, slopes, and other accessibility features. Staff validated the data with a smart level and ensured the technology provided accurate and repeatable measurements. The city is now analyzing the data in a database and GIS system to prioritize barrier removal and bring sidewalks into compliance with ADA standards.

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Making Bellevues Sidewalks Accessible for Everyone TRB 2012 Annual Meeting Paper: 12-1439 Franz Loewenherz Senior Transportation Planner City of Bellevue (WA)
ADA Culture of Compliance
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).
Title II Elements
Bellevue ADA Sidewalk & Curb Ramp Self Evaluation
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
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
Bellevues Approach 1 2 3 Data Collection Database Analysis Barrier Ranking Disability Community Participation
Data Collection
ADA Curb Ramp Inventory
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.
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.
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.
ULIP Data Transfer Data Capture Data Acquisition GIS Integration Data Processing
Quality Assurance/Quality Control
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
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 Levels 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)
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
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.
Change in Level Output Reports Field Validation Mode ASCII text file Data in Citys GIS QA/QC
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 ULIPs 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.
Roadway Grade Analysis
Measurement of Grade Maximum grade is defined as a limited section of path that exceeds the typical running grade.
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.
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
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
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 Citys Transition Plan document.
Digital Elevation Model Calculation 134 miles
Digital Elevation Model Calculation 134 miles 95 miles
Digital Elevation Model Calculation 134 miles 95 miles 39 miles
Driveway Cross Slope Analysis
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.
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.
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.
Cross Slope Findings 1. Over 50% of Bellevues 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.
ADA Viewer Interface
Identify/ Print ADA Viewer Window Navigation Extents Locate by Toggle Bar Navigation Address Legend/ Layers Location Map
Trb paper 12 1439 (11-23-12)
Trb paper 12 1439 (11-23-12)
Barrier Ranking Analysis
Compliance vs. Accessibility ADA tells us which features are non-standard ... But it doesnt tell us which of these non-standard features should be replaced first.
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
Barrier Ranking Analysis Land Use Ramps Streets Paths Census Islands Activity Impedance Barrier Score Score Ranking
Legend
Legend
Legend
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
Thank you Franz Loewenherz Senior Transportation Planner City of Bellevue 450 110th Ave. NE Bellevue, WA 98009 floewenherz@bellevuewa.gov Phone: 425.452.4077

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Trb paper 12 1439 (11-23-12)

  • 1. Making Bellevues 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).
  • 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. Bellevues Approach 1 2 3 Data Collection Database Analysis Barrier Ranking Disability Community Participation
  • 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
  • 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 Levels 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 Citys 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 ULIPs 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.
  • 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 Citys 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
  • 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 Bellevues 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.
  • 37. Identify/ Print ADA Viewer Window Navigation Extents Locate by Toggle Bar Navigation Address Legend/ Layers Location Map
  • 41. Compliance vs. Accessibility ADA tells us which features are non-standard ... But it doesnt 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
  • 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