Drivers in far-flung parts of the D.C. region will encounter new traffic patterns this week on some major projects. Over the upcoming holiday weekend, transit users will see the first of 2012’s Metro station shutdowns for maintenance.

Today, Wednesday and Thursday are the days when travelers are most likely to see rain, but throughout the week, temperatures will remain on the mild side of winter, the Capital Weather Gang says.

11th Street Bridge

The District Department of Transportation has opened the second span of the new 11th Street Bridge. This span takes traffic away from downtown D.C. The new inbound span opened in mid-December.

Drivers coming from downtown D.C. who are heading to neighborhoods just east of the Anacostia River will need to remember that this new outbound span has a new traffic pattern designed for through traffic, not local traffic.

Until the new local span opens this summer, they will need to use one of several detours:

— Exit the freeway at the Sixth Street SE ramp, continue east on Virginia Avenue SE, turn right on Eighth Street SE, then left on M Street SE and then right on 11th Street SE and onto the old outbound bridge. On the east side, drivers will use new bridges over I-295 and the railroad tracks to reach Martin Luther King Jr. Avenue SE.

— Exit the freeway at South Capitol Street, take the Douglass Bridge over the river, continue to Suitland Parkway, turn left on Firth Sterling Avenue SE, turn right on Howard Road SE.

— Continue on the new outbound freeway river bridge to southbound I-295 and exit at Howard Road SE.

— Continue eastbound on the freeway to Pennsylvania Avenue and take the Sousa Bridge to Minnesota Avenue.

See more about the 11th Street Bridge project on the Commuter page.

Metrobus detours

Several Metrobus routes will detour between 8 p.m. and 5 a.m. daily through Jan. 27 to accommodate work on the 11th Street Bridge project.

Routes 90, A42, A46, A48, P2, P6 toward Anacostia: Buses will use Howard Road SE from I-295 south to Anacostia station.

Routes B2, U2 toward Anacostia: Buses detour between 17th Street SE and Minnesota Avenue SE and Martin Luther King Jr Avenue SE and Morris Road SE.

Route 92 toward Congress Heights: Buses detour between I-295 south and Howard Road SE and 13th Street SE and Good Hope Road SE.

Route 93 toward Congress Heights: Buses detour between Howard Road SE at I-295 south and Martin Luther King Jr. Avenue SE before resuming regular route on Morris Road SE.

Cleveland Park elevator

The entrance elevator at Metrorail’s Cleveland Park station is out of service for a modernization project that will continue through May.

Shuttle bus service will be provided to or from the Woodley Park station for people who can’t use Cleveland Park without the elevator in operation. Riders also could choose to travel via Metrobus routes L1, L2 or L4 between Cleveland Park and Woodley Park.

University Boulevard paving

The Maryland State Highway Administration this week plans to continue paving University Boulevard between Arcola Avenue and Colesville Road (Route 29).

There may be single lane closings from 9 a.m. to 3 p.m. weekdays.

Route 29/Linton Hall Road

Over the weekend, traffic in Gainesville shifted onto the recently completed detour roads where the Virginia Department of Transportation is working on separating Route 29, Linton Hall Road and the railroad tracks.

The traffic shift clears the way for construction of two overpasses. One will carry Route 29 over the railroad tracks. The other will take Linton Hall Road and Gallerher Road over Route 29 and the tracks.

The project also will widen Route 29 to six lanes from Interstate 66 to Virginia Oaks Drive. It’s scheduled to be done in the middle of 2015.

George Washington Parkway

The National Park Service project to stabilize the rocks along the George Washington Parkway in Rosslyn continues this week, but the contractor is preparing to shut down for the winter..

From 9:30 a.m. to 2:30 p.m. weekdays, the northbound left lane may be closed just north of the Spout Run Parkway exit. All lanes will be open during rush hours.

Constitution Avenue

From 5:30 a.m. to 7 p.m. weekdays, drivers may find up to two lanes in each direction closed on Constitution Avenue NW for the National Park Service road rehabilitation project between 23rd and 15th streets.

Dulles Metrorail

The Dulles Metrorail project is ready to start building the pedestrian access pavilion across Route 123 from what the planners call the Tysons East station. The pavilion, at Route 123 and Colshire Drive, will be the ground-level entrance for the pedestrian bridges over Route 123.

Building the foundation will require workers to drive in 38 steel piles, and it will be noisy. The pile-driving will be performed between 7 a.m. and 5 p.m. on weekdays and occasionally on Saturdays for about three weeks.

The project says nearby residents at the Gates of McLean and along Anderson Road are likely to hear the noise. So will employees at Capital One, some buildings owned by Cityline Partners and at Northrop Grumman and MITRE.

Construction of similar pavilions will get underway soon at the other four stations farther west along the new line.

Route 7 in Tysons Corner

On the west side of Tysons Corner, the Dulles Metrorail project continues construction of the rail bridge in the median of Leesburg Pike (Route 7). The construction over the Spring Hill Road intersection is wrapping up, project officials say. When the work is done, the big blue-and-yellow truss used to build these guideways will move west, through the future Tysons West station and over the intersection of Tyco Road/Westwood Center Drive.

The advancing work means the middle of either intersection may be closed between 11 p.m. and 5 a.m. through Friday. Work on the rail project will continue all this year.

Metro’s weekend plan

During the upcoming Martin Luther King Jr. holiday weekend, Metro plans to renew the track work program that shuts some rail stations and uses buses to bridge the gaps in train service. The first round of 2012 will split the Orange and Blue lines in central D.C.

For the three-day weekend, buses will replace trains between L’Enfant Plaza and Eastern Market. The Federal Center SW and Capitol South stations will be closed. In the work zone, Metro will be replacing track switches. The switch replacements, recommended by the National Transportation Safety Board, are big jobs requiring lots of space and time. So they often are the reason for the weekend shutdowns.

Many maintenance projects on the Red, Blue, Orange and Yellow lines are scheduled to shut various stations through the winter, before a bit of a break around the time of the Cherry Blossom Festival.