Travelers will encounter cool, dry weather most of this week in the D.C. region, the Capital Weather Gang says, though there is a chance of showers on Thursday and Friday. During prime trick-or-treat hours this evening, the temperature will drop from the low 50s into the upper 40s, and skies will be cloudy.

Union Station’s main hall reopened after weekend work, Metro now allows free transfers between the Farragut rail stations, Maryland raises tolls on its bridges and tunnels Tuesday. See more details on these and other events in transportation this week.

Halloween safety

The days are growing shorter, and plenty of children will be out after dark. These safety tips are from the Maryland State Highway Administration:

Drivers, stop for pedestrians; speeding makes it more difficult to stop unexpectedly; be especially cautious during peak trick-or-treating hours between 4 and 9 p.m.; enter and exit driveways slowly; be alert for children darting across the street or crossing between parked cars.

Pedestrians, look left, right and left again before crossing the street; cross at crosswalks or intersections; avoid dark clothing; and use reflective devices such as vests and blinking lights; avoid costumes that may impair vision; make eye contact with drivers when crossing streets; watch for speeding cars.

Union Station hall reopened

Union Station’s main hall reopened at 3:30 p.m. Sunday after closing Friday evening for emergency repairs after a piece of plaster fell from the ceiling. The probable cause of the problem was damage from the Aug. 23 earthquake.

Farragut transfers

Metrorail riders who want to switch between lines at the Farragut North and Farragut West stations in downtown Washington no longer have to pay a separate fare, as long as they are using SmarTrip cards.

This virtual tunnel, which Metro has dubbed the Farragut Crossing, allows free transfers between the Blue and Orange lines at Farragut West and the Red Line at Farragut North. Just remember it’s a virtual tunnel. You still have to get out and walk between the stations. Riders have 30 minutes to make the free switch between stations.

Metro at Braddock Road

Crews are scheduled to do weekday track work near the Braddock Road station, where Metro needs to replace worn ties and upgrade the surface under the rails. The work will be done at midday Mondays through Fridays for the next three weeks, starting Monday. (This Tuesday will be skipped because a statue of Ronald Reagan will be unveiled in a ceremony from 11 a.m. to noon at Reagan National Airport.)

From 10 a.m. to 2 p.m. on the workdays, trains will share a single track between Braddock Road and National Airport. Yellow Line trains will operate every 18 minutes between Huntington and Mount Vernon Square. Riders between Mount Vernon Square and Fort Totten should use Green Line trains.

Blue Line trains are scheduled to operate every 18 minutes between Franconia-Springfield and Largo Town Center.

Metro weekend work

For this coming weekend, Metro plan to use free shuttle buses to replace trains between Glenmont and Fort Totten on the Red Line. The Takoma, Silver Spring, Forest Glen, Wheaton and Glenmont stations are scheduled to be closed from Friday night through the train system’s midnight closing on Sunday.

11th Street Bridge

The District Department of Transportation plans to temporarily close the 11th Street SE entrance ramp to the outbound 11th Street Bridge between 10 p.m. and 5 a.m. Monday through Thursday nights this coming week. During those hours, workers will demolish the retaining wall along the ramp.Pedestrian access will be maintained at all times.

Detour: Motorists traveling on M Street SE and 11th Street SE will be detoured to Eighth Street SE to reach the outbound bridge.

Kalmia Road

The District Department of Transportation will temporarily close the curb lanes on Kalmia Road NW between East Beach Drive and West Beach Drive next week for preliminary work on replacing a culvert in the area.

The curb lanes will be closed between 9:30 a.m. and 3 p.m. Monday and Tuesday. A single lane in each direction will be kept open along this stretch of Kalmia Road.

Maryland tolls rising

The fee increases on Maryland’s bridges and tunnels are set to take effect Tuesday. On the Bay Bridge, for example, the toll goes from $2.50 to $4. On the Nice Bridge (Route 301) in Southern Maryland, it goes from $3 to $4. Tolls on both bridges will rise again in July 2013 to $6.

There’s a change in tolling on the Intercounty Connector, but it affects only those drivers who don’t use an E-ZPass transponder.

Those who get a bill based on a video recording of their license plate number will see that the $3 Notice of Toll Due fee is replaced with a video toll rate that is 1 1 / 2 times the toll.