At a developer's conference this evening, the MBTA will announce plans to give access to real-time bus location data on all its bus lines by the end of the summer.

In the meantime, the T is immediately releasing data on 12 bus lines, in addition to the five already covered by its "Where's the Bus" system. The new routes: 1, 4, 15, 22, 23, 28, 32, 57, 66, 71, 73, and 77. They join the 39, 111, 114, 116, and 117 routes.

Although the data is public, it's not in a human readable form. Over the past year or so, the T has worked with local application developers to build a variety of applications that people can use on everything from smart phones to electronic signboards.

Also, MBTA General Manager Richard Davey says he will soon go on Twitter.