DAVID GIONGCO Caltrans Local Assistance Engineer

Proposed Changes to CBC, Access Standards – Comments Due 12/10

Several proposed California Building Code changes that affect curb ramps on highway/street projects were submitted to the Building Standards Commission.  The public commenting period is currently running and ends on December 10.  Once approved, the changes will be effective January 2014.
If you would like additional information on the proposed changes or provide comments, links are included in the following message from HQ Division of Design:

The California Department of General Services, Division of the State Architect (DSA), has submitted a code revision of the California Building Code (CBC) to the Building Standards Commission (BSC) to modify the accessibility standards to meet or exceed the federal 2010 ADA Standards. Once approved, these code changes will affect any highway/street project that proposes curb ramps or impacts existing curb ramps and the adjacent pavement, such as pavement rehabilitation. The effective date is for January 2014.

The BSC has posted the proposed CBC version for the 45 day public commenting period currently running from Oct 26 to Dec 10. Those of you who have submitted comments for the BSC Sept 25-27 public meeting will note that there have been no changes in the proposed CBC version that DSA has submitted to the BSC for the 45 day public commenting period. You can obtain information about the proposed CBC changes and the public commenting form at http://www.bsc.ca.gov/codes/adoptcycle/3rd45DayCommentPeriod.aspx. Click on the bar Division of the State Architect – Accessibility (DSA/AC). The proposed code changes can be seen under Express Terms of Chapter 11B. The specific sections pertaining to curb ramps and pavement/shoulders are in 11B-406.


DSA has rewritten the California Building Code (CBC), access provision, for the purpose of obtaining USDOJ certification that the code meets or exceeds the ADA requirements. The model federal code for accessibility is the 2010 ADA Standards, which replaced the ADAAG. The ADAAG and the 2010 ADA Standards were written for buildings and facilities. But, until the federal draft Public Rights of Way Accessibility Guidelines (PROWAG) is finalized and binding, we have to use applicable portions of the 2010 ADA Standards for our public rights of way projects.

There are problems and impacts to public rights of way that the changes to the CBC creates that affects Caltrans and any other highway/roadway agency subject to the CBC.

Here are the specific issues:

Clear Space Within ETW

In addition to following the 2010 ADA Standards language, the proposed CBC incorporates sections of the draft PROWAG, which isn’t even final or adopted by the USDOJ or the USDOT. Much of the draft PROWAG is controversial and Caltrans is on record of opposing some of these provisions. One part of the PROWAG that the proposed CBC is incorporating is a section having to do with a clear space at the bottom of the curb ramp that is out of the traveled way. This will now create a mandated 4 ft shoulder wherever we have a curb ramp. Here is the proposed CBC language:

11B-406.5.9 Clear Space. Beyond the bottom grade break, a clear space 48 inches (1219 mm)
minimum by 48 inches (1219 mm) minimum shall be provided within the width of the pedestrian street
crossing and wholly outside the parallel vehicle travel lane. At marked crossings, the clear space shall
be within the markings.

Incidentally, this same clear space area out of the ETW is in the 2010 ADA Standards. However, it is in the context of a single diagonal curb ramp at the apex of the corner. In this context, it would be out of the ETW, but in the proposed CBC it can apply to the double curb ramp which puts it within the ETW if we have less than a 4 ft shoulder.

Top Landing for Parallel Curb Ramps

By melding the 2010 ADA Standards with language from the draft PROWAG, a mandated top landing for the parallel curb ramp is now created. No landing requirement is stated in the 2010 ADA Standards for a parallel curb ramp (Case C curb ramp in Standard Plan A88A) because a parallel curb ramp is not mentioned or shown in the illustrations. A perpendicular curb ramp (Case A curb ramp in Standard Plan A88A) is the type shown in the 2010 ADA Standards illustration as having a top landing. See Figure 406.4 below.

Here is the proposed CBC language:

Under Common Requirements that applies to the perpendicular and parallel curb ramps, it says…
11B-406.5.3 Landings. Landings shall be provided at the tops of curb ramps and blended transitions.
The landing clear length shall be 48 inches (1219 mm) minimum. The landing clear width shall be at
least as wide as the curb ramp, excluding any flared sides, or the blended transition leading to the
landing. The slope of the landing in all directions shall be 1:48 maximum.

The complication is created is when the highway is on a grade and the sidewalk follows the same grade. We are currently able to provide a curb ramp that will go from the sidewalk grade to a 1:12 (8.3%) grade for a parallel curb ramp. But, this revision will make us provide a 4 level landing first and then ramp down at 1:12. This is also a problem at corners with driveways near the corner. We will now need extra length to provide a level landing of 4 ft on each side. With a double parallel curb ramp (doubles are an advisory standard in Index 105.5 of the HDM) this becomes very lengthy and we will have to purse R/W (easements, fee,..) or have to relocate the private driveway and probably compensate the owner.

Also, we already implied no top landing requirement, in the Curb Ramp Scoping and Design Memo, for the parallel curb ramp. See diagram below.

Pavement Reconstruction

The proposed CBC is continuing the 4 ft language addition to the Counter Slope requirement; the 4 ft is currently in the CBC, which has gone beyond the federal ADAAG or 2010 ADA Standards for years. The 2010 ADA Standards requires a 5% max slope at the adjoining surface at the bottom of a curb ramp; no 4 ft or any dimension is stated. This matches our shoulder cross slope standard in new construction, but over time with pavement overlays the 5% is exceeded. A curb ramp project or a CAPM project is not scoped to do any extensive pavement reconstruction to accommodate the 4 ft at 5% provision. We are able to follow the 2010 ADA Standards requirement because a 4 ft distance is not prescribed; we can handle that in the gutter pan per HDM 303.2, 836.2(2), and Standard Plan A87A Note 10. Here’s the wording of the CBC:

11B-406.5.8 Counter Slope. Counter slopes of adjoining gutters and road surfaces immediately
adjacent to and within 48 inches (1219 mm) of the curb ramp shall not be steeper than 1:20. The
adjacent surfaces at transitions at curb ramps to walks, gutters, and streets shall be at the same level.