Pedestrian Handrail Geometrics 1

[breaks]

AASHTO has guidelines for pedestrian railings on highway bridges in Section 2.7.3. In this section, it states that "all elements of the railing assembly shall be spaced such that a 6-inch sphere will not pass through any opening. For elements between 27 and 42 inches above the walking surface, elements shall be spaced such that an eight-inch sphere will not pass through any opening."

In past(non-bridge)projects, I have designed railings for platforms using OSHA criteria, and the minimum spacing of railing members was not used.

My question is: if I'm designing a handrail for a pedestrian ramp (no vehicular traffic at all) using the ADA (American Disabilities Act) Code, do the AASHTO geometric criteria apply? The ADA Code says nothing about the spacing of the structural members.

Thanks.

 

[Ron]

There are two considerations to make here. First, most of the building codes address this issue and most now require design such that a 4-inch sphere does not pass. Secondly, this requirement is consistent with the Life Safety Code (NFPA 101).

The 6-inch sphere requirement remained in many codes until recently. Most have change to be consistent with the Life Safety Code.

I'm fairly sure the ADA addresses only the height, grip diameter, extension, and structural capacity of the handrails.

Ron

 

[Qshake]

I agree with Ron. You need to take a look at the building codes for the area in which the structure is located(UBC, BOCA etc). The AASHTO code doesn't apply here. Also, the criteria has be updated from the 6" to 4" sphere and is in AASHTO's design guidelines of pedestrian bridges (the exact title escapes me now).