• Erika Springer-McCaffrey

Detectable Warning: Several Changes in Code Updates

This week in our code update series we are discussing detectable warning. There are several code changes that impact detectable warning installation. Last week we looked at installation of detectable warning at parallel curb ramps. You can find that information here if you missed it. This week we are looking at other changes including changes to color requirements and several added sections that prohibit the use of detectable warning in various locations.



First we'll look at:

11B-705.1.1.3 Color and contrast. Detectable warning surfaces at transit

boarding platform edges, bus stops, hazardous vehicular areas, reflecting

pools, and track crossings shall comply with Section 11B-705.1.1.3.1.

Detectable warnings at other locations shall comply with either Section

11B-705.1.1.3.1 or Section 11B-705.1.1.3.2. The material used to provide

visual contrast comply with this section shall be an integral part of the

detectable warning surface.

Exceptions:

1. Replacement of less than 20 percent of existing detectable

warnings at a single contiguous location shall be permitted to be

in-kind at existing curb ramps, islands, or cut-through medians

with detectable warnings in compliance with the code

requirements in effect at the time of installation.

2. Existing installed detectable warnings at curb ramps, islands, or

cut-through medians may comply with Section 11B-705.1.1.3.2

in lieu of Section 11B-705.1.1.3.1.


11B-705.1.1.3.1 Detectable warning surfaces shall be yellow and

approximate FS 33538 of Federal Standard 595C 33538 of SAE AMS-STD-595A.


This is a big change from previous code cycles that allowed for different colored detectable warning in some circumstances. The requirements are now strictly for yellow detectable warning, unless the detectable warning is previously installed and less than 20 percent is being replaced. This change also eliminates the ambiguous language of "hazardous vehicular area" which we see also being changed in 11B-705.1.2.5.


11B-705.1.2.5 "Hazardous vehicular areas Blended transitions.

Detectable warnings at hazardous vehicular areas blended transitions

shall be 36 inches (914 mm) in width.

(We previously discussed the changes to the definition of blended transitions in this code cycle as well. You can read that here.)


Next, we are going to go over 9 codes that have changes all of which prohibit detectable warning being installed in specific areas. Some of them may surprise you as DW is commonly installed in these areas. However, the application of detectable warning is often misunderstood and therefore installed incorrectly, creating more harm than good. We have had many client discussions urging them to remove detectable warnings that were installed in these areas and as access specialist are happy to see some clarity being brought to the code.

We attended a Certified Access Specialist Institute workshop about these code changes and the speaker, John Caprarelli, made a great analogy about detectable warning installation that we wanted to share to hopefully help with the design of where it should and shouldn't be installed. Detectable warning is used by the visually impaired to understand when they are leaving a safe pedestrian area and entering a hazardous vehicular area. So detectable warning can be thought of as an on/off button for the user.

Let's say a visually impaired shopper leaves a grocery store and is following the raised circulation path (more on that next week!) once they hit a piece of detectable warning they know that they are leaving a safe pedestrian area and entering the vehicular area. In good design, they would not come across detectable warning again until they are back onto the raised circulation path.

So with all that, here are nine areas that detectable warning should never be installed according to the newest code cycle.


11B-304.2 Floor or ground surfaces. Floor or ground surfaces of a turning

space shall comply with Section 11B-302. Changes in level, slopes exceeding

1:48, and detectable warnings shall not be permitted. are not permitted. (11B-304 references Turning Spaces)


11B-305.2 Floor or ground surfaces. Floor or ground surfaces of a clear floor

or ground space shall comply with Section 11B-302. Changes in level, slopes

exceeding 1:48, and detectable warnings shall not be permitted. are not

permitted. (11B-305 references clear floor or ground space)


11B-404.2.4.4 Floor or ground surface. Floor or ground surface within

required maneuvering clearances shall comply with Section 11B-302.

Changes in level, slopes exceeding 1:48, and detectable warnings shall

not be permitted. are not permitted. (11B-404 references doors, doorways, and gates)


11B-405.7.1 Slope. Landings shall comply with Section 11B-302. Changes in

level, slopes exceeding 1:48, and detectable warnings shall not be permitted.

are not permitted. (11B-405 references ramps)


11B-502.4 Floor or ground surfaces. Parking spaces and access aisles serving

them shall comply with Section 11B-302. Access aisles shall be at the same

level as the parking spaces they serve. Changes in level, slopes exceeding 1:48,

and detectable warnings shall not be permitted. are not permitted. (11B-502 references parking spaces)


11B-503.4 Floor or ground surfaces. Vehicle pull-up spaces and access aisles

serving them shall comply with Section 11B-302. Access aisles shall be at the

same level as the vehicle pull-up space they serve. Changes in level, slopes

exceeding 1:48, and detectable warnings shall not be permitted. are not

permitted. (11B-503 references passenger drop-off and loading zones)


11B-504.4 Tread surface. Stair treads shall comply with Section 11B-302.

Changes in level, slopes exceeding 1:48, and detectable warnings shall not be

permitted. are not permitted. (11B-504 references stairways)


11B-802.1.1 Floor or ground surface. The floor or ground surface of

wheelchair spaces shall comply with Section 11B-302. Changes in level,

slopes exceeding 1:48, and detectable warnings shall not be permitted. are

not permitted. (11B-802 references wheelchair spaces, companion seats, designated aisle seats and semi-ambulant seats)


11B-812.3 Floor or ground surfaces. Vehicle spaces and access aisles serving

them shall comply with Section 11B-302. Access aisles shall be at the same

level as the vehicle space they serve. Changes in level, slopes exceeding 1:48,

and detectable warnings shall not be permitted in vehicle spaces and access

aisles. (11B-812 references electric vehicle charging stations)


Next week we will discuss raised circulation paths briefly on the blog. This topic has raised lots of questions with our readers and LinkedIn followers, so we are excited to let you know that not only we will be covering the changes on the blog, but also are offering a free 1 hour training on the new updates with a dedicated time for Q&A. Save the date for Nov 4th at 10am (PST) and be on the look out for registration details next week.

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