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Re: Google Trip Planner

for

From: Benjamin Hawkes-Lewis
Date: Jun 18, 2008 1:20PM


Tom Kort wrote:

> Is Google Transit generally know as accessible to the visually
impaired? A
> Chicago Transit Authority press release
>
(http://www.transitchicago.com/news/ctaandpress.wu?action=displayarticledetail&;articleid=100614)
> said it was, but I have my doubts,

I applaud your press release scepticism.

There's a more helpful discussion about what this accessibility claim
actually
entails from T. V. Raman, who is both a screen reader developer (sort of, he
develops emacspeak) and a Google developer, at:

http://googleblog.blogspot.com/2008/01/public-transit-made-easy.html

The accessibility claim seems to boil down to the following:

1. The main interface includes some text providing information as well as a
map.

2. You can get just a plain-ish HTML version without the map by appending
&output=html to the URL. (Not sure how end-users are supposed to find out
about this.)

3. Third-party programmers could write specialized software to
use the raw data Google provide.

> Google Transit doesn't seem to have headers.

Agreed.

> It seems that the summaries are too breif and don't present useful
> information like route numbers or walking distance,

I'm not entirely sure what you're referring to as "the summaries" here. The
page you link to does include a bus number (152). Based on what Raman
says, it
would show walking distances between stops, if any applied, but not
walking as
an alternative to driving or taking public transport.

> and of course their format is not what is suggested by accessibility
guides.

Well probably, but given you're ensuing question: in which particular sense?

> Is this a problem?

Well, accessibility is not a boolean. Just because someone, somewhere judges
Google Transit accessible to the visually impaired doesn't mean it doesn't
pose any unnecessary problems to the visually impaired. It also doesn't say
/anything/ about accessibility to people with other disabilities; note that
people with visual disabilities might be in both groups.

> I tried looking at the source code and saw things like
> "x3ex3cnobrx3ex3c." What is this code?

That's a part of an arbitrary HTML string inside a JS string.

Specificially, nobr is a non-standard element:

http://msdn.microsoft.com/en-us/library/ms535856(VS.85).aspx

Some of the characters in the string are presented as hexadecimal escapes:

http://bclary.com/2004/11/07/#a-7.8.4

For example x3c is an escape for <. This may be a precautionary measure
against strings being interpreted as HTML markup and ending the SCRIPT block
prematurely:

http://lachy.id.au/log/2005/05/script-comments

The string will presumably be inserted into the HTML document object
model at
some point via methods such as:

http://developer.mozilla.org/en/docs/DOM:document.write

http://developer.mozilla.org/en/docs/DOM:element.innerHTML

--
Benjamin Hawkes-Lewis