ADA Sidewalk and Curb Ramp Compliance Requirements Guide:

Understanding PROWAG and How ADAM Supports Accessibility

Introduction

Ensuring ADA Sidewalk and Curb Ramp Compliance is crucial for safe, accessible pedestrian infrastructure.  It is more than a best practice – it’s a federal requirement. On August 8, 2023, the U.S. Access Board published the final rule for Accessibility Guidelines for Pedestrian Facilities in the Public Right-of-Way (PROWAG). These guidelines, which took effect October 7, 2023, define clear requirements for sidewalks, curb ramps, crosswalks, islands, and related elements to ensure universal accessibility.

Rieker Inc.’s ADAM (Advanced Data Acquisition & Measurement) system simplifies inspections for ADA Sidewalk and Curb Ramp Compliance across public right-of-way projects and enables municipalities, engineers, and contractors to assess, measure, and document compliance efficiently and defensibly. This page breaks down the PROWAG requirements and shows how ADAM supports complete ADA Sidewalk and Curb Ramp Compliance investigations and reporting for all types of pedestrian infrastructure.

ADA curb ramp assessment

ADA curb ramp assessment

ADAM Zone Analysis of dimensions, slope, and transition heights

PROWAG Requirements for Sidewalks

Clear Width

  • Minimum pedestrian access route: 48 inches (1.2 m).
  • Exceptions apply when physical constraints prevent full width, but passing spaces must be provided.

Running Slope

  • Maximum of 5% (1:20) unless following street grade.
  • If steeper, route is considered a ramp and must meet ramp criteria (handrails, landings).

Cross Slope

  • Must not exceed 2% (1:50) to ensure wheelchair stability and drainage compliance.

Surface Conditions

  • Surface must be firm, stable, and slip-resistant.
  • Changes in level over ¼ inch must be beveled or ramped.

Passing Spaces

  • If clear width is less than 60 in, provide a 60 x 60 in passing space every 200 ft.

How ADAM Supports ADA Sidewalk and Curb Ramp Compliance Efforts:

  • The ADAM Assessment Module is designed for rapid field evaluations and, while it does not offer high-precision measurements compared to the ADAM Compliance Module, its slope and distance calculations typically fall within the dimensional tolerances accepted by the ADA. (Access Board Guidance on Tolerances)
  • This makes the Assessment Module a dependable tool for identifying potential noncompliance and guiding decisions on where more detailed compliance checks or engineering models may be needed.
  • Using built-in mobile device sensors and telemetry from Rieker inclinometers, the system effectively captures cross and running slope values, and allows for surface condition observations and event annotations tied to GPS.
  • Measurements and findings are documented and organized per job, improving consistency and reducing human error in early-stage assessments.

PROWAG Requirements for Curb Ramps

Slope and Width

  • Running slope: Maximum 1:12 (8.33%)
  • Cross slope: Maximum 2%
  • Minimum width: 48 inches (1.2 m)

Landing Area

  • A level landing of at least 48 in (L) x 48 in (W) must be provided at the top of each ramp. Some jurisdictions allow a minimum 36 in (W) in certain contexts, but 48 x 48 inches is the prevailing standard for new construction.

Detectable Warnings

  • Required where pedestrian paths meet vehicular ways (e.g., curb ramps at street crossings).
  • Must be truncated domes in a contrasting color and texture.

Flared Sides

  • If no handrails or edge protection, flared sides must not exceed 1:10 slope.

Island Ramps

  • At pedestrian refuge islands, ramps must provide a 48 x 36 in level area at the top.

How ADAM Enables Accurate Curb Ramp Compliance:

  • The ADAM Compliance and Engineering Modules are purpose-built to meet the exacting requirements of PROWAG for curb ramps, landings, and transitions.
  • Using the Automated Reference Plane (ARP) and Measurement Validation Plates, these modules deliver NIST-traceable results with precision up to ±0.1″, ensuring objective and reproducible data for all slope, width, and landing measurements.
  • In addition to real-time measurements in the field, the 3D Infrastructure Model generated by ADAM allows users to extract exact dimensions from the model even after leaving the site—supporting audits, redesigns, or legal documentation without the need to re-inspect.
  • This system ensures compliance is not only measured but also documented and preserved with full traceability. to capture slope and landing data that is NIST-traceable.
  • Users can extract precise dimensional data from the 3D model, even after the fieldwork is complete.

ADAM’s Modular Support for ADA/PROWAG Compliance

Curb Ramp and Sidewalk Analysis icon

Assessment Module

  • Uses mobile device sensors and cameras paired with Rieker Inc’s proprietary sensors for fast documentation
  • Records geolocated measurements and event observations
  • Offers guided workflows to prompt required inspections
  • Enables early-stage evaluations or large-scale
ADAM ADA Curb Ramp Compliance

Compliance Module

  • Incorporates high-accuracy inclinometer data
  • Measures slope, cross slope, and ramp alignment to ADA/PROWAG specs
  • Produces legally defensible, NIST-traceable reports
Engineering Point Cloud

Engineering Module

  • Builds a full 3D Infrastructure Model of the curb ramp or sidewalk site
  • Includes point cloud, textured mesh, and images with orthophotos available on request
  • Enables engineers to assess and redesign from the desktop

Legal, Technical, and Documentation Benefits

  • The Rieker Report follows standardized compliance format based on ADAAG and PROWAG
  • All data and models are stored securely and linked to job ID, location, and timestamp
  • Reports support remediation planning, legal proceedings, and audit readiness.
  • Custom State Compliance Reports are available and can be configured to match the format, layout, and language required by each state, including any unique local measurement or documentation standards.

Learn More About ADAM

Continue to discover how ADAM simplifies PROWAG compliance from field assessment to engineering documentation.

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