There is a multitude of criteria that must me met to make a curb ramp ADA compliant, including, but not limited to, longitudinal grade, cross-slope, material, texture and color. One criterion that is often over-looked and omitted from design specifications is the use of “detectable warnings.”

The 1991, Americans with Disabilities Act Accessibility Guidelines (ADAAG) requires that curb ramps have detectable warnings, complying with Section 4.29.2. Detectable warnings are a distinctive surface pattern of truncated domes. The domes are intended to be detectable by cane or underfoot, and are used to alert people with vision impairments of their approach to streets (in the absence of a definitive cue, such as a curb) and hazardous drop-offs. They are also required along the edges of boarding platforms in transit facilities, the perimeter of reflecting pools, and adjacent to sidewalks which cross or adjoin a vehicular way (and the walking surfaces are not separated by curbs, railings, or other elements between the pedestrian areas and vehicular areas).

Section 4.29.2 of ADAAG specifies “Detectable warnings shall consist of raised truncated domes with a diameter of nominal 0.9 in (23 mm), a height of nominal 0.2 in (5 mm) and a center-to-center spacing of nominal 2.35 in (60 mm), and shall contrast visually with adjoining surfaces, either light-on-dark, or dark-on-light.”

In 1994, the Architectural and Transportation Barriers Compliance Board (Access Board) temporarily suspended the requirements for detectable warnings, due to concerns raised about the specifications, availability of complying products and maintenance issues. The suspension applied to all requirements for detectable warnings, except those at boarding platforms in transit stations. The United States Department of Justice (DOJ) and Department of Transportation (DOT), the agencies that enforce the design requirements of the ADAAG standards, also joined the Access Board in this action.

During the suspension, the Access Board sponsored additional research on detectable warnings, and also conducted a comprehensive review of ADAAG. In addition, it resumed work on developing a supplement to ADAAG, specific to public rights-of-ways.

The detectable warning suspension expired July 26, 2001, and no action was taken to maintain the suspension or remove the requirement of detectable warnings from ADAAG. As a result, the requirements for detectable warnings at curb ramps are again part of ADAAG, and once again enforceable standards.

Since many local municipalities’ standard details do not include detectable warnings in their curb ramp details, many private projects are not being specified with detectable warnings, and are therefore, not in compliance with ADAAG standards. Proper consideration and design during the planning stages of the development and use of appropriate standards and details will eliminate this potentially costly design error.

On March 7th and 14th, Harris Kocher Smith is hosting the first of an ongoing workshop series informing engineers and surveyors about better ways to meet ADA guidelines and comply with current standards.

A Super Observation
By Phil Card

Today’s land development environment is all about meeting the customer’s needs without going over budget. Along with the necessity of hiring a competent engineering firm to design a project, management of the construction phase may be equally, if not more, important. Even a great design will not meet land developers’ expectations if it is improperly constructed.

Construction operations can be fast moving and unforeseen problems are likely to be uncovered. Daily, on-site observation by a qualified Construction Manager (CM) can help the course of a project flow more smoothly from finished design to completed project. On-site observation gives the Project Engineer and Project Owner job site representation that can ensure they are aware of actual field conditions, which in turn can make dealing with any design questions that arise a faster, more efficient process. Also, on-site observation can safeguard that unforeseen conditions are properly noted, problems are corrected and that adequate testing is performed within a timely manner.

The CM can also guarantee that concrete pours are properly prepared and the Engineer has been notified of any potential problems or changes. Observation of operations can ensure that the asphalt paving was correctly placed and all field modifications for milling, tie-ins or driveways are properly documented. If traffic has direct impact on the project, an experienced CM can help tweak the traffic control plan to address unexpected conditions and minimize the effects on the public to as little as possible.

A major cause of headaches on any project is Pay Request verification. By independently measuring, calculating, inspecting and documenting a project, the CM can verify that the billed amount is the correct amount. The CM can also work with the contractor’s project manager to determine whether submitted pay requests are being billed correctly, contain all required documentation, and that the calculations are accurate.

A project can consist of anything: a simple, short section of curb and gutter; a complex bridge with abutments, decks and retaining walls; a subdivision with utilities, infrastructure, roadways and mixed use development. Regardless of the complexity of your project, having an experienced Construction Manager to carefully monitor every step of a development guarantees that all phases are completed according to schedule and are in compliance with codes and standards, making certain that the developer is pleased with the product received.