The new spider maps show 15 key bus routes, for the first time, along with subway lines, commuter rail lines, and the Silver Line enhanced bus service. The first map went up today in Government Center station. Eventually, the new maps will go up in every subway, commuter rail stop, trolley stop, and bus terminal. Smaller maps with a few less details will go up in subways and trains.

The T replaces old route maps every few years, but this is the first major systemwide upgrade in a long time, though officials could not say exactly how long.

The neighborhood map that was also replaced in Government Center had not changed since 1967, when the station was known primarily as Scollay Square. It showed, for example, the old elevated highway where the Rose Kennedy Greenway now sits, as well as a planned linear office building near Faneuil Hall that instead became the Holocaust Memorial.

The new spider maps still have a few quirks -- including showing a Silver Line link between from Washington Street to South Station that will not be in service until next month. "Would you prefer we put up maps now and then again in a month?" said Joe Pesaturo, MBTA spokesman, in response to a question about potential confusion. "It's already been over 40 years."

The map replacement project is expected to take two years and cost a total of $500,000 -- including labor and production, Pesaturo said.