Delays are slowing down commuters all over the tracks Tuesday afternoon. 

The Red Line is experiencing the most severe delays, with Boston Fire Department activity keeping movement to a crawl along the entire line, according to MBTA real-time service alerts. No word as of 5 p.m. on what that activity is.

A disabled train is causing moderate delays along the B branch of the Green Line.

So far, Orange Line, Mattapan Trolley and Silver Line riders are still in for a clear ride home.

No such luck for bus riders. As of 5 p.m., 49 bus lines are experiencing slowdowns thanks to rush-hour traffic. 

On the commuter line, Kingston Train 048, which departed at 4:02 p.m. is running an hour behind schedule due to an earlier disabled train. The Fitchburg line is running about a half hour behind, while a Franklin train, Haverhill train, a Lowell train and a Middleborough train are all running 10 to 20 minutes behind schedule.

No serious accidents, but typical traffic is slowing down commuters along Route 93 and 90, according to MassDOT real-time traffic data.