Also prominent on the new home page is a feature called “Plan & Ride,” which lets users find door-to-door directions across several modes of transportation. The feature is similar to HopStop.com and the authority’s own TripPlanner application, although entering a search sends users directly to a Google Maps page.

Image Real-time updates on delays will be among the information featured prominently on the site. Credit... Metropolitan Transportation Authority

“When you open up a Web site, you say, ‘Where do I want to go?’ ” Mr. Walder said. “You could not find an airline or a car rental company or anything like that that doesn’t have the what-do-you-want-to-do feature right at the front of their page.”

The authority already licenses its scheduling data to Google, and Mr. Walder said that it made more financial sense to take advantage of an already popular outside service rather than to continue investing in a proprietary application.

The new site will also make it easier for outside software designers to get free access to system timetables and routes.

Except for Amtrak, the Metropolitan Transportation Authority receives more Web traffic than any other public transit agency in the country. At its peak, in November 2008, the authority’s Web site had more than 1.8 million unique visitors and about 25 million page views, according to data compiled by the Nielsen Company.

In November 2009, the site had about 1.1 million visitors, more than Greyhound or Avis.

Not all of the site’s 9,000 pages will be updated when the new version goes online. Officials described the new site as a work in progress, and mobile tie-ins for the BlackBerry and the iPhone are in development.

Web designers who were asked to compare both versions of the site said that the overhaul was an improvement, but that the authority still had a ways to go.