After encountering a few showers Monday, travelers will find the weather getting a bit warmer and sunnier for the rest of the week, the Capital Weather Gang says. Today, the sun rose at 7:05 a.m. and will set at 6:50 p.m. As the days shorten, the low sun or dim light may become more of a factor in your commute.

Capital Beltway drivers in Virginia who so often encounter a changed landscape have an important new issue to deal with this week: the closing of the left exit from the inner loop to westbound Interstate 66. Transit riders in D.C. should note changes in the Circulator bus routes.

Here’s what you should know about these plans and other conditions that will affect your travels in the D.C. area this week.

Beltway exit closing

Drivers approaching Exit 49C, the left exit from the inner loop (northbound I-495) to westbound I-66, should find it closed today. Instead, they will use the ramp on the right side, Exit 49A. The right exit ramp will have two lanes to accommodate the additional traffic.

This change will be tricky for drivers accustomed to using the left exit, and probably will cause some extra traffic congestion until they get used to it.

Exiting motorists will need to be in the right lane as they approach the I-66 interchange. The merge onto Exit 49A has been relocated to before the I-66 overpasses. By the time a driver sees the closed exit go by, it’s going to be too late to move across the Beltway to the open exit.

This closing is required to continue construction of the high-occupancy toll lanes. Traffic will be shifting to the new Beltway outer lanes, and work will begin on a new access ramp to the HOT lanes

Rock Creek Parkway

Monday through Wednesday, milling operations will be underway on the southbound lanes of Rock Creek Parkway between Beach Drive and Waterside Drive. Lane closings are scheduled for 9:30 a.m. to 3:30 p.m.

Nighttime paving also has begun between P Street and Beach Drive and will continue through Friday, from 7 p.m. and 6 a.m. each night.

Constitution Avenue

From 5:30 a.m. to 7 p.m. each weekday, expect to find up to three westbound lanes closed on Constitution Avenue between 23rd and 17th streets for milling, road base repair, sidewalk installation and streetlight work. At least two lanes will be open for travel in each direction during rush hours. Also, some temporary lane closings will occur for various jobs, such as light pole and sign replacements.

From 7 p.m. through 5:30 a.m. each night through Friday, expect to find up to three lanes closed in each direction between 23rd and 17th streets. From 9 p.m. to 5:30 a.m. Thursday night, either 18th Street or Virginia Avenue just north of Constitution Avenue may be closed to traffic for paving operations.

Fairfax flood damage

The Virginia Department of Transportation is repairing roads and bridges across Fairfax County that have been closed because of the flooding from Tropical Storm Lee in early September.

The most recent rains haven’t helped, said Garrett Moore, VDOT’s district administrator for Northern Virginia. But by Friday, he expects Hunter Mill Road to reopen. Repairs to Carper’s Farm Way and Walker Road, which were damaged but not closed to traffic, will also be completed this week, he said.

VDOT said other roads and bridges closed by the storm should reopen by the end of October or mid-November.

Washout in Charles County

Heavy rains washed out part of Budds Creek Road (Route 234) in Charles County three weeks ago. The Maryland State Highway Administration has announced it will install a temporary bridge over Allens Fresh Run, east of Route 301. The temporary bridge will be about 100 feet long and have two 12-foot wide travel lanes capable of carrying all legal loads. SHA said it expects to open the bridge by the end of November.

Third Street/Riggs Road NE

The District Department of Transportation has temporarily created a new traffic pattern on Third Street and Riggs Road NE in the Fort Totten area. This is related to the intersection reconstruction at South Dakota Avenue and Riggs Road.

On Third Street between Riggs Road and Second Street, the northbound lane has been reopened. Traffic will be kept on the west side of the street, with one lane in each direction.

On Riggs Road between Chillum Place and First Street, traffic is shifting to the north side of Riggs Road. Two inbound lanes and one inbound lane will be kept open.

The sidewalk on the south side of Riggs Road between South Dakota Avenue and Chillum Place has closed.

On South Dakota Avenue between Riggs Road and Kennedy Street, traffic will remain on the west side of the avenue. One southbound lane and two northbound lanes will be kept open. Drivers will be permitted to make a left onto Riggs Road from both northbound lanes.

Bridges over I-395

The District Department of Transportation plans to start construction this month on the Air Rights Tunnel project in Northwest Washington. The Air Rights Tunnel takes Interstate 395 traffic under Massachusetts Avenue NW, north of the Third Street Tunnel.

Construction is scheduled to continue through spring 2013. The project will rehabilitate the bridges over I-395 on H and K streets and Massachusetts Avenue.

The bridge surfaces will be upgraded and improvements will be made to the drainage system, traffic signals, street lighting and sidewalks, DDOT said. Some upgrades will also be made in the tunnel below the bridges to improve the lighting and air exchange.

Construction is scheduled for 9 a.m. and 4 p.m. weekdays and may also occur on weekends as needed. At a minimum, DDOT said, one lane will be kept open in each direction on the bridges, and at least two lanes in each direction will be open in the tunnel.

D.C. Circulator changes

The District Department of Transportation is launching a series of changes Monday in the Circulator bus system, eliminating one route, adding another and making further adjustments in the service.

Convention Center-SW Waterfront: The Convention Center-Southwest Waterfront Circulator is being eliminated after the end of Friday night’s service. A new Metrobus, Route 74, started operating this week along the Seventh Street corridor between the Washington Convention Center and the Waterfront neighborhood. The 74 bus costs more to ride and offers less frequent service, but the District said the ridership on the Circulator was too low to continue it.

Anacostia route: DDOT said it will add a route Monday serving neighborhoods east of the Anacostia River for the first time. The route will run from the Potomac Avenue Metrorail Station to Skyland via Barracks Row (Eighth Street SE), but the exact route has not yet been published..

Union Station-Navy Yard: Also effective Monday, DDOT will adjust the route of the Navy Yard-Union Station buses. They no longer will travel west on Constitution Avenue and north on Louisiana Avenue to reach Union Station.

Instead, they will stop on Columbus Circle at the flag poles adjacent to Union Station before turning right on F Street NE and right again on Second Street NE to reach Constitution Avenue.

That means they no longer will stop inside the Union Station garage. Stops on Louisiana Avenue and D Street also will be eliminated.

Bus stop consolidations: On the Georgetown-Union Station and Dupont Circle-Georgetown-Rosslyn routes, some stops that are close together will be combined or eliminated.

Stops at 18th, 19th and 20th streets along K Street NW will be combined into one stop at K Street and 19th Street NW, heading west toward Georgetown. Stops at 18th and 19th Streets on K Street NW will be combined into one stop at K and 19th streets NW, heading eastbound toward Union Station.

Stops will be eliminated at Wisconsin Avenue and P Street NW, both eastbound and westbound; at Wisconsin Avenue and N Street NW heading westbound, and at M and 31st streets NW heading eastbound.

A stop will be added at 35th Street and Wisconsin Avenue, where the Georgetown-Union Station buses turn around to head back toward Union Station.

The consolidations and eliminations of some stops seem like good moves for the overall service, though they will be an inconvenience for some riders.

The Circulator needs to come closer to maintaining the bus-every-10-minutes service that is as much a part of its reputation as the distinctive style of the buses.

Circulator/ART transfers: Riders transferring from Arlington Transit (ART) buses to the Circulator will start receiving a free transfer when paying with their SmarTrip cards. Those transferring from the Circulator to ART will pay 50 cents.

Metro open early Sunday

On Sunday, Metrorail will open at 6 a.m., an hour early, for the Army 10-Miler race. On the Blue Line, extra trains will run from 6 to 8 a.m. and from 11:15 a.m. to 12:40 p.m. Blue Line trains toward the Pentagon will leave Franconia-Springfield and Stadium-Armory every 7½ minutes.

Bus service at the Pentagon Transit Center will be relocated to Pentagon City until all streets are reopened around 2 p.m.

The best rail stations for participants and spectators will be Pentagon or Pentagon City on the Blue and Yellow Lines. On weekends, parking is free at lots and garages operated by Metro.

Metrorail weekend delays

This will be a big weekend for maintenance disruptions on Metrorail. On the Green and Yellow lines, buses will replace trains between Georgia Avenue and Mount Vernon Square. The Shaw, U Street and Columbia Heights stations will be closed while workers install new track switches. Also this weekend, buses will replace Orange Line trains between East Falls Church and West Falls Church. In this area, crews on the Dulles Metrorail project are working to link the new line with the Orange Line.