When the 30-day Orange Line shutdown ended on Sept. 19, MBTA officials said riders could expect slow zones on parts of the for five to seven days while newly installed track settled. But more than two weeks later, riders complain the train is still slow — especially between North Station and Assembly Square.

Adding to riders’ frustrations has been a lack of communication from the MBTA about why the slowdowns have continued. On Wednesday, the MBTA finally revealed it had decided to do additional track work on the Orange Line, above and beyond what was originally planned during the shutdown, largely because work crews and construction materials were already in place.

The transity authority offered little information on when the speed restrictions might end.

Well beyond the promised one-week waiting period, commuters were left wondering for days why the trains are still moving so slowly between North Station and Assembly Square. Many complained on social media that the delays are causing them to be late for important events. Some said it was worse than the shuttle buses, which the MBTA provided as alternate transit for Orange Line riders during the shutdown.

T officials said that, since the additional construction work would have to be done in the future anyway, they decided to do it now.

Despite several requests from GBH News for futher information, the MBTA did not describe the work being done or how it relates to the slowdowns. In a brief statement, an MBTA spokesman only said that the work is being done during overnight hours when passenger trains are not running, but the daytime slow zones will continue until that work is done.

The MBTA did not offer a target date or time line for when speed restrictions in that area will be lifted.