A number of public officials and the founders of Google assembled at Grand Central Terminal on Tuesday to announce the start of New York’s version of Google Transit, an online feature that they said would transform the experience of navigating New York City’s transit system, the nation’s busiest.

“It is a very complicated transit system, and it just got less complicated today with the advent of Google Maps for transit,” Gov. David A. Paterson said, noting that the subway system opened with 9.1 miles of lines in 1904, and that the Metropolitan Transportation Authority now serves a territory of 5,000 square miles.

The array of public officials present reflected Google’s economic might, particularly at a time when Wall Street’s convulsions have left the city and state economy reeling. Not only did the governor and leaders of the transportation authority attend the Grand Central news conference, but so, too, did Deputy Mayor Edward Skyler, representing the Bloomberg administration, and officials of the Port Authority of New York and New Jersey and of New Jersey Transit.

“It just gives me great personal pleasure to be able to help even in a tiny way this fantastic public transportation system,” Sergey Brin, one of Google’s founders, said at the news conference. The company’s other founder, Larry Page, said he even hoped the tool would “help congestion, help the economy over all.”