Halloween isn’t until Monday, which means a lot of people will be celebrating the holiday on Saturday night. (Depending on how the weather shakes out, what with the the unseasonable cold and potential snow.)

Once again, the Washington Regional Alcohol Program will sponsor free cab rides home for adults in the Washington region. SoberRide is available from Saturday at 10 p.m. until Sunday at 6 a.m. The program will cover up to $30 in cab fare, so you’re responsible for anything over $30. Just call the 1-800-200-TAXI (8294) for your ride. (AT&T customers can dial #TAXI or #8294.)

The fine print: You have to be 21 years old to utilize SoberRide. Calls must originate in D.C. or in specific jurisdictions in Maryland (Montgomery and Prince George’s counties as well as Rockville, Bowie, College Park, Gaithersburg, Greenbelt and Takoma Park) and Virginia (Arlington, Fairfax, Prince William and Eastern Loudoun counties as well as Alexandria, Falls Church, Fairfax, Manassas and Manassas Park).

You can’t reserve a ride or schedule a pickup time in advance. This is a popular program, so remember that no matter when you call, you’ll likely have to wait a while.

After the jump, some tips from Dr. Gridlock for people who will be out late celebrating the holiday this weekend:

As Dr. Gridlock pointed out earlier today, there will be delays on four of the five Metro lines from Friday at 10 p.m. until the system closes on Sunday night. These could have a serious impact on Halloween revelers who want to use public transit, so take note:

— Red Line trains will single track between Dupont Circle and Judiciary Square. From 9:30 a.m. to 9 p.m. on Saturday and Sunday, trains will leave the ends of the line (Shady Grove and Glenmont) every 10 minutes. Every other train from Shady Grove will end at Dupont Circle, while every other train from Glenmont will end at Union Station.

At all other times — particularly the late hours on Saturday night, when people will be out — Red Line trains will leave the ends of the line every 20 minutes or so. This means that Red Line trains on Saturday night will be very, very crowded. Riders traveling through downtown are advised to use the Metrobus and Circulator as alternatives.

If you’re planning to be out until the last train leaves, take note: The last trains from Glenmont will leave 11 minutes earlier than usual on Saturday and Sunday (2:26 a.m. on Saturday and Sunday and 11:26 p.m. on Sunday).

— Several stations will be closed on the Green and Yellow Lines: Waterfront, Navy Yard, Anacostia and Congress Heights. Shuttle buses will move riders between these stations, but this could add 30 minutes of travel time for some riders.

The last train leaves Branch Avenue 20 minutes earlier than usual (at 2:04 a.m. on Saturday and Sunday and at 11:04 p.m. on Sunday).

— Orange Line trains will single-track between New Carrollton and Cheverly. As a result, every other Orange Line train heading to New Carrollton will end at Cheverly and head back to Vienna. Traveling through the work zone could add 20 minutes to your trip.