MBTA GENERAL MANAGER Steve Poftak said the new Orange and Red Line cars will remain in limbo for the time being as the T continues to try to reach consensus on what caused a derailment in March and what can be done to remedy the problem or problems.

Two weeks ago the deputy general manager, Jeffrey Gonneville, said an Orange Line train derailed near the Wellington train yard in Medford on March 16 due to “a series of contributing factors.” He also disclosed that the T and CRRC Mass., the Chinese train manufacturer, were at odds over the principal cause. He said he hoped to have a plan for returning the cars to service shortly.

On Monday, Poftak said little has changed.

“We are continuing to work not only internally but with a number of external partners to work on a plan to get those cars back in service,” Poftak said. “Engaging with our outside regulators as well, with a goal of getting those cars back in service this summer. We hope to be able to share with the public a more detailed timetable once we‘re able to put that plan fully together.”

The new Orange Line train was moving from one track to another at slow speed in a work zone when it derailed. Initial concerns focused on a 46-year-old switch, but subsequently the T zeroed in on break pads that were wearing down faster than expected and other problems with the switch and the track itself.

There was no “single point of failure” that caused the derailment, Gonneville said two weeks ago.

All of the T’s 252 Red and 152 Orange line vehicles are being replaced by CRRC.

Gulliver says most traffic back to 2019 levels 

State Highway Administrator Jonathan Gulliver said traffic levels on most roadways have returned to 2019 levels.

In a briefing for the Massachusetts Department of Transportation board, Gulliver repeated what he said on the CommonWealth Codcast last week – that traffic has returned to the highly congested levels last seen in 2019.

Gulliver said traffic remains down on the Massachusetts Turnpike and the tunnels to and from the airport. He said the nature of traffic has changed – drivers are taking shorter trips closer to home and congestion is spread throughout the day with morning and evening peaks shorter in duration.