The Red Line experienced severe delays on Monday morning due to a speed restriction on the Longfellow Bridge, grinding transit in both directions to a congested crawl.

“Due to a speed restriction as a result of Longfellow Bridge track work performed on January 23 and 24, the Red Line is experiencing delays in service,” MBTA spokesman Joe Pesaturo said. “This speed restriction is anticipated to be cleared in two to three days with regular Red Line service resuming at that time.”

The bridge, which connects Kendall/MIT and Charles/MGH, has been under construction as part of MassDOT’s $3 billion Accelerated Bridge Program.  Pesaturo said that when new track is installed, "some time is required to allow it to settle before trains can operate at regular speeds over it."

“The trains have to slow down to 10 mph,” Pesaturo said. “The MBTA will lift the speed restriction as soon as it is safe to do so. Customers are asked to allow some extra time for their commutes.  The MBTA will provide constant updates on its website, through T Alerts, message boards on platform, and on twitter @mbta.”

Local transit watchdogs Transportation For Massachusetts called Monday's delays "unacceptable."

“This inconvenienced a lot of riders, it’s clearly unacceptable for something that could have been foreseen could inconvenience a bunch of riders on a Monday morning,” Charlie Ticotsky, Policy Director at T 4 Mass said. “We think it would be helpful if they could strengthen their customer communication by letting riders know why these delays are happening. So many people were stuck in [Monday’s] delays without any idea why. They had no idea this was going on.”

Busses have been running between Park Street, Charles/MGH and Kendall/MIT on weekends as MassDOT construction crews worked on the rail line. 

"Putting a 10 mile speed restriction on a half-mile stretch of track shouldn't have impacted travel like this," Jeremy Mendelson Advocacy Director for TransitMatters said. "We know the rail has to settle after they do construction, but they cannot run any more trains, and are already opperating at capacity. The issue with the Longfellow is is that we waited so long to update this project that now crucial and was held off until the last minute."