The MBTA said on Friday morning that there were a number of delays related to the weather system.
MBTA crews were seen clearing snow from the green line in Boston after more than a foot of snow fell.
Later, the MBTA Transit Police tweeted that all lines had regular service.
“#MBTA Red, Orange, Blue, & Green: Regular service resumed. Continue to be cautious, careful, & safe as surfaces may be slippery #MAsnow,” it wrote.
Earlier on Friday, the MBTA experienced systemwide delays due to the snow.
It wrote before: “Roads are snow covered and slippery. If you don’t have to go out, stay home so that plows can continue to clear roads. #MAsnow.”
MBTA spokesman Joe Pesaturo told the BostInno website that MBTA crews are working to prevent system breakdowns due to the cold.
“Single-digit temperatures can wreak havoc with aging equipment,” he sad.