Metrorail had delays throughout the week, but trains kept running despite snow and extreme cold. (Nikki Kahn/The Washington Post)

The week’s snow and cold affected both drivers and transit users, but the biggest disruptions occurred on Metrorail lines.

In his monthly report to the Metro board on Thursday, board chairman Tom Downs focused on the impact of the cold temperatures, a likely cause of that morning’s cracked rail, which slowed riders on the Blue and Yellow lines during rush hour. Downs recognized “the difficulty the system has operating when the temperature is in single digits. Cracked rail is a phenomenon that everybody who operates a railroad understands. Large changes in temperature can easily fracture rail. There is no cure for it. … The only thing I can say to our customers is that we’re sorry and we try to repair the damage as quickly as possible when it occurs.”

Richard Sarles, Metro’s general manager, talked about Tuesday’s snow. “Throughout the storm,” he said, “Metrorail and Metrobus continued serving our riders, and Metro’s parking lots and stations remained plowed, salted and shoveled …

“While some of our equipment is feeling the effects of the deep freeze that followed the storm, our employees deserve special recognition for their hard work through the storm and this week as they battled the cold to keep people moving.”

Snow totals on Tuesday were the deepest in the region in four years, but they did not force Metrorail to curtail above-ground service. Metrobus limited service to its snow emergency routes late Tuesday and early Wednesday.

Government and school closings, followed by delayed openings, sharply reduced rush hour ridership. But those who did travel encountered problems throughout the week. Not all the problems were related to the snow and cold. As the storm intensified Tuesday afternoon, signal problems and train equipment problems — usually doors and brakes — led to delays of up to 20 minutes, according to Metro reports.

During Wednesday’s big chill, service on all lines was disrupted by track and train problems. The most common cause of delay was a brake problem. Out of 51 incidents logged by Metrorail on Wednesday, 22 were attributed to brake problems. Five trains had door problems. During the rush hours, most delays reported by Metro were under 10 minutes. But at 8:23 a.m., a Blue Line train experienced a brake problem and unloaded passengers at the Arlington Cemetery station, an outdoor platform, resulting in a 14-minute delay on the line.

At 9:25 a.m., an Orange Line train was offloaded at McPherson Square (underground) because of a brake problem, and riders were delayed 24 minutes. At 4:12 p.m., passengers had to get off a Green Line train at College Park (outdoor platform) because of a door problem, resulting in an 18-minute delay.

The delays listed here are from Metro’s reports for the week. Passengers waiting for trains often send out Twitter messages giving longer times for the delays. They also experience the residual effects of delays in that they may have to pass up trains that are just too crowded to board. A Wednesday morning Tweet from Sarah Dunn: “Longest Metro ride this a.m. in 4 yrs living in D.C.; 90 min. from Dunn Loring to McPherson. Usually takes 30 min.!

Also, the tidiness of the aftermath reports masks the uncertainty riders experience during the disruptions. Many complain that they aren’t getting enough information over the loudspeakers in the stations and on the trains to estimate the length of a disruption or figure out alternative routes. A Wednesday Tweet from Brian W.: “Are any OL [Orange Line] trains moving? Been sitting at Clarendon for 30 min. and seen no trains.”

The worst disruptions on Thursday affected riders on the Blue, Yellow and Green lines. During the morning rush, many riders on the Blue and Yellow lines were delayed about a half-hour because of a cracked rail between Braddock Road and Reagan National Airport. Workers had to install a new 39-foot section of rail. Meanwhile, trains traveling in both directions shared the one open track around the problem area. Rails can crack when they experience sharp changes in temperature, such as the 50- degree swing that occurred this week.

Near the start of the Thursday afternoon rush, a fire on the tracks between Archives and L’Enfant Plaza delayed riders on the Green and Yellow lines. Trains shared a track between Mount Vernon Square and L’Enfant Plaza. Metro estimated the resulting delays at up to 20 minutes, The Washington Post’s Mark Berman reported.

On the roads
During such Metrorail disruptions, some riders speculate about whether they would have been better off driving. It’s difficult to compare the results this week. Road crews benefit far more from government and school shutdowns than does Metrorail, because the lack of traffic gives the plows a much better chance at keeping lanes open. The difference between this Tuesday afternoon’s relatively easy commute in snow and the ghastly eight-hour commutes of Jan. 26, 2011, was the federal government’s timely decision to close offices for the day. The delayed openings on Wednesday morning also helped.

The region’s highway departments acknowledged the difficulties involved in the cleanup: They urged people to stay off the roads during the height of the storm.

During Friday morning’s commute, the major travel disruption occurred on Rockville Pike, where an early morning water main break near White Flint Mall shut down traffic in both directions. The Post’s Dana Hedgpeth reported at 10:36 a.m. that lanes have reopened both ways.