MBTA hopes to remove some speed restrictions on the Green Line tomorrow, but says riders should still expect longer trips on all lines

Interim MBTA General Manager Jeff Gonneville says the T is continuing to work through a morass of track defects across all four subway lines and that he hopes to lift the "global" speed restrictions on the Green Line with the start of service on Saturday.

But at a press conference this afternoon, he said that the Green Line, like the Red, Orange, Blue and Mattapan lines will continue to have extra "block" slow zones - on top of the ones that were already in place - as T inspectors and a separate set of outside inspectors go through all the problems. The slow zones are on top of the increased time between trains because of a shortage of dispatchers at the T's central operations center.

So, he said, riders in general, and St. Patrick's Parade-goers this Sunday in particular, should continue to plan for their rides to take longer. He said the T will be running shuttle bus service from South Station to South Boston on Sunday. The T will also continue to let riders transfer at certain Red and Orange Line stations to parallel commuter-rail service for free, he said.

These "block" speed restrictions will be lifted as either the defects are fixed or inspectors determine whatever the issues are don't require fixes. The reason for the initial systemwide slowdown was that inspectors from the state Department of Public Utilities discovered track issues on the Ashmont branch of the Red Line and then the T couldn't prove that earlier defects had actually been fixed.

"I remain focused on the safety of fixing the system," Gonneville said, adding that once all the inspections and repairs are finished, the T will take "necessary actions to ensure this never happens again."

About the images: Eadweard Muybridge is better known for his pioneering images of speeding racehorses, but in 1887, he painstakingly did a study of sloth locomotion.