A cyclist pedals down the bike lane on L Street NW in the District. (Matt McClain/For The Washington Post)

Friday is the brightest day of the weekend, before clouds and showers move in, the Capital Weather Gang says.

About 12,000 participated in Friday’s Bike to Work Day. They still need to get home, so please watch for the extra pedal traffic Friday afternoon. On Thursday morning, a 20-year-old bicyclist was critically injured when he was hit by a car along the U Street corridor, according to D.C. police.

On Sunday, allow extra time if you’re trying to take Metro to the University of Maryland graduation ceremony at 1 p.m. in College Park, because of the track work along the Green Line. Metro also will be working on the Orange and Red lines.

D.C. United plays Sporting KC at 5 p.m. Sunday in RFK Stadium. The Nationals are still on the West Coast.

Several other traffic-generating events are coming up this weekend. The main delays for road work are likely to be found south of D.C. in the 95 Express Lanes construction zone on I-95/395.

HIGHLIGHTS: Metro | I-95/395 closings | Capitol Hill Classic | Taste of Arlington

Friday activity at Bethesda medical center

From 11 a.m. to 3 p.m. Friday, the Walter Reed National Military Medical Center in Bethesda is hosting a staff appreciation day barbecue on its front lawn. That means it will be visible from Rockville Pike, as will two skydivers at about 11:30 a.m., so watch out for slow traffic because of rubbernecking.

Gate 2, the one directly across from the Medical Center Metro station, will be open for bicycles and pedestrians, but closed to vehicle traffic from 9 a.m. till the event is over.

Metro weekend delays

Disruptions for maintenance on the Red, Orange and Green lines begins at 10 p.m. Friday and continues through the Metrorail system’s closing at midnight Sunday. (My Sunday column has a letter from an Orange Line rider who got stuck in Friday night confusion at Ballston last week.)

Red Line. Trains will share a track between Van Ness and Dupont Circle, and between Rhode Island Ave and Takoma. They are scheduled to operate every 24 minutes between the ends of the line at Shady Grove and Glenmont. Between Dupont Circle and NoMa-Gallaudet, more trains will be in service. In that middle zone, trains should arrive about every 10 minutes during the daytime.

Orange Line. Free shuttle buses will replace Orange Line trains between East Falls Church and Clarendon. The Ballston and Virginia Square stations will be closed. Trains will operate on a regular weekend schedule between Vienna and East Falls Church, and between Clarendon and New Carrollton.

The buses between East Falls Church and Clarendon will stop at Ballston and Virginia Square. Taking them all the way will add about 25 minutes to normal travel time, Metro said.

The last trains from Vienna to East Falls Church will leave at 1:57 a.m. on Friday and Saturday nights and at 10:57 p.m. on Sunday.

Green Line. Shuttle buses will replace trains between Greenbelt and West Hyattsville. The Greenbelt, College Park and Prince George’s Plaza stations will be closed.

Trains will operate on their regular weekend schedule between West Hyattsville and Branch Avenue. The buses between Greenbelt and West Hyattsville will stop at College Park and Prince George’s Plaza. Add about 35 minutes to normal travel time if taking the entire bus route.

I-395/95 closings

Starting at 11 p.m. Friday, the Virginia Department of Transportation plans to close the high occupancy vehicle lanes on I-395/95 from the D.C. line to the end at Route 234 in Dumfries. At 10 a.m. Saturday, the HOV lanes will reopen from south of the Franconia-Springfield Parkway (Route 289) to Dumfries.

The northern section from Washington D.C. to south of the Franconia-Springfield Parkway will remain closed until 10 a.m. Sunday, when the entire HOV system opens northbound.

VDOT will close the left lane on I-395 South between Seminary Road and the Capital Beltway from 11 p.m. Friday until 10 a.m. Saturday, and again during the same hours Saturday night.

I-95 shoulder widening project

Two right lanes on I-95 South will be closed between the Cardinal Drive overpass and Dumfries Road and on I-95 North between Opitz Boulevard and the Prince William Parkway from 10 p.m. Friday to 9 a.m. Sunday and from 9:30 p.m. Saturday to 9 a.m. Sunday for milling and paving.

Rhode Island Avenue

The District Department of Transportation plans to close the left lane in both directions on the 100 block of Rhode Island Avenue NW starting Saturday and continuing till Aug. 23. Workers will install a large storm sewer. Sometimes, the right lane also will be closed.

Sunday’s Capitol Hill Classic

About 3,500 runners will be on the streets of Capitol Hill starting at 8:30 a.m. Sunday for the Capitol Hill Classic 10K race. The course is different this year. It starts at Stanton Park and goes past RFK Stadium, then onto the Anacostia Riverwalk Trail. See a course map.

Starting at 5:30 a.m. Sunday, the street on the south side of Stanton Park will be closed between Fourth and Sixth streets for the event setup. Then the streets along the course will be closed as the runners pass by. The race should be over around 11:30 a.m.

Taste of Arlington

The annual Taste of Arlington street festival is scheduled for noon to 5 p.m. Sunday in Ballston. It will close these streets from midnight through 10 p.m. on Sunday.

  • Wilson Boulevard eastbound at Glebe Road
  • Wilson Boulevard westbound at North Randolph Street
  • North Stuart Street between North Ninth Street and Wilson Boulevard

All traffic southbound on North Taylor Street from Fairfax Drive will be forced to go westbound at Wilson Boulevard. Street parking in the area will be restricted. Watch for  temporary “No Parking” signs. Illegally parked vehicles may be ticketed or towed. If you get towed from a public street, call 703-228-4252.

Douglass Bridge testing

The District Department of Transportation plans to close the Douglass Bridge on South Capitol Street for testing of the swing span from 4 to 9 a.m. Sunday.