While legal considerations might be your biggest worry, making your site more accessible is simply good customer service. More than 39 million Americans are blind and another 246 million have "low vision," Another one million are deaf in the U.S. Add to that people with mobility issues that prevent them from using their hands and that's a huge portion of the country's buying power.
If you return your availability by room type your our online booking engine must also display and hold accessible rooms only for people with disabilities until all other rooms have been booked. (Rule becomes effective March 15, 2012.) If you return your availability by individual units you do NOT have to hold ADA rooms back until all other units have been reserved. However, all other ADA regulations do apply (ADA room descriptions, using a booking engine that is ADA compliant, and making your website ADA accessible).
Talk to your web designer about other techniques that will make your site more user-friendly for people with disabilities. Worried that’s not in your budget? Consider the fact that DOJ fines start at $75,000. And it's still yet to be determined if a non-compliant website is liable for one fine or will be charge per page for each violation. As the recent lawsuits illustrate, though, settlements quickly add up into the millions.