DC Metro Safetrack surge #6

The Washington DC subway system (Metro) is undergoing a series of safety surges where they are either shutting down sections of track or "single" tracking over sections. Surge #6 affects the red line and I am having trouble understanding how frequently the trains will run. The documentation I have says:

Red Line trains between Shady Grove to NoMa every 6 minutes
Red Line trains between Glenmont to Grosvenor every 12 minutes

The Shady Grove and Glenmont stations are the ends of the lines. There are depots at the NoMa and Grosvenor stations.

How long will I have to wait for a train when I am heading from:

NoMa to Grosvenor
Grosvenor to NoMa

Finally, if the waits going in the two directions are different, what happens to all the "extra" trains?

public-transport washington-dc

Best Answer

Under normal operations, around half of the Red Line trains operate the entire length of the line, from Shady Grove to Glenmont, and half operate an abbreviated route from Grosvenor to Silver Spring. Normal headways during rush hour would be every 6 minutes for each service. Because the services overlap, however, a rider boarding in the downtown direction would expect a train every 3 minutes between Grosvenor and Silver Spring.

Because of the SafeTrack "surge," which severely reduces the capacity of the Red Line between Silver Spring and Takoma, the endpoints for these services have shifted. Instead of an abbreviated service and a full service overlapping in the middle, you have two abbreviated services with different endpoints overlapping in the middle. They still overlap, however, so in theory, you should expect a train at least every 4–6 minutes during rush hour.

Although the work is being done between Silver Spring and Takoma, NoMa-Gaulladet is the turnaround point because there is a yard at Rhode Island Ave-Brentwood, one stop north, where the trains can be reversed more easily.

In practice, things will be a mess during rush hour, so consider the bus or other alternatives.