Passenger walking to bus stop

Where Are Detectable Warnings Required by US Law?

The purpose of detectable warning tile systems is to protect pedestrians of all abilities from hazards such as vehicular traffic and mass transit. According to the standards released by the Americans with Disabilities Act (ADA) and the Architectural Barriers Act (ABA), most public spaces are expected and required to equip detectable warning dome tiles.

The ABA and ADA Standards not only address the specifications of warning dome tiles including diameter, spacing, and height, but these standards also outline where detectable warning systems should be placed in buildings, sidewalks, and public spaces.

Where To Expect Detectable Warning Systems

You can commonly find detectable warning systems in public spaces, especially mass transit platforms, crosswalks, and curb ramps. Detectable warning systems were developed to aid individuals with disabilities, but they also benefit pedestrians and cyclists who may not be paying attention to their surroundings.

Railway Station Boarding Platforms

Platform boarding edges in rail stations that do not have any protection by guards or platform screens should feature detectable warnings 24 inches wide along the full length of the platform’s public usage area (§810.5.2 and §705.2). The DOT ADA Standards, the ABA Standards, and DOJ require this.

Bus Station & Underground Transportation Boarding Platforms

Platforms with drop-off edges require detectable warning dome tiles to warn transit users of that drop-off as well as to indicate how far away to stand from the edge. Often these platforms include navigational tiles as well to direct individuals with vision impairments to exits and to transit.

Curb Ramps

The ADA Standards that the DOT issues for public transportation facilities state that curb ramps require detectable warnings. As per the standards, they should extend the curb ramp’s full width, excluding the flared sides. Also, they must extend either a minimum depth of 24 inches (measured on the surface of the ramp from the curb’s back) or the curb ramp’s full depth.

This requirement to ADA Standards (2006) of DOT applies to facilities that local and state governments use to offer public transportation.

Public Spaces & Community Areas

ADA standards require that publicly used spaces are equipped with detectable warning systems. This includes areas around escalators, stairs, pedestrian crossings, parking garages, transit platforms, and wheelchair ramps.

These ADA detectable warning requirements prove to be vital in the creation of an accessible space. Some of the sections of the ADA Accessibility Guidelines (ADAAG) that indicate detectable warning surface requirements for detectable warning system installations are:

R304.1 General - Detectable warnings should feature a surface of truncated domes that are aligned in a radial grid or square pattern and must comply with R304.

R304.1.1 Dome Size – In detectable warning surface truncated domes should have a minimum of 23 mm (0.9 in) as the base diameter to a maximum of 36 mm (1.4 in), a minimum top diameter of 50% of the base diameter to a maximum 65% of the base diameter, and 5 mm (0.2 in) as height.

R304.1.2 Dome Spacing - In detectable warning surface truncated domes must have a minimum of 41 mm (1.6 in) as center-to-center spacing and a maximum of 61 mm (2.4 in), and a minimum of 17 mm (0.65 in) as base-to-base spacing, measured between the most adjacent domes.

Basically, the purpose of detectable warning dome tiles is to alert individuals with a variety of abilities, whether impaired or not, of their approach to hazardous drop-offs, heavily trafficked areas, and street crossings. ADA detectable warning dome tiles were developed to aid individuals with disabilities, and our world is made more accessible by the use of warning systems.

At StrongGo, we strive to make the world more accessible for all, and our ADA compliant detectable warning dome tiles make that happen. Reach out today to discover ADA solutions for your company, university, or city center. 



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