The open-doored Metrorail cars that allowed passengers to walk between platforms have been replaced with a walkway. (Metro photo)

The train bridge that allowed Metro riders to walk through its open doors and pass from platform to platform has been removed from the Reagan National Airport station.

The parked rail cars have been replaced by a short bridge over the tracks between the platforms. Getting the cars out of there allows Metro to proceed with the rebuilding of track switches at the station.

Train bridge at airport station The two-car “train bridge” allowed riders to walk through open doors across the platform. (Robert Thomson – The Washington Post)

The goal of the switch project is to allow northbound or southbound trains to cross over the tracks in either direction. Today, those movements are limited. Riders can spot the problem if they stand at the ends of the airport station platforms and view where the middle tracks go — or don’t go. A northbound train heading for the District can’t be shifted via the middle track to what is normally the southbound side, and a southbound train can’t transfer to what is normally the northbound side.

Metro managers want more flexibility to handle disruptions. “The current configuration means that if, for example, we have a disabled inbound train at Crystal City, the single-tracking around it would run all the way from Braddock Road to Pentagon City (with delays exceeding 30 minutes),” Metro spokesman Dan Stessel said in an e-mail. “With a double crossover at National Airport, the single tracking zone would be much shorter — National to Pentagon City — and more like 15-20 minute delays.”

Having access to the middle, or “pocket” track from both of the main travel tracks also will make it easier to turn back trains from the airport station if the need arises. Track configurations at Mount Vernon Square, Silver Spring, Grosvenor, West Falls Church and Stadium-Armory allow for similar turn back operations.

The switch project is scheduled to be done by early summer, Stessel said. On one weekend before work is done, the platform bridge will need to be removed to clear room for the track work.

The train bridge and the metal walkway were installed as temporary measures during an elevator rebuilding project. During my online discussion Monday, a traveler noted that the train bridge was gone.

While the train bridge was in place, several riders asked why Metro had chosen to use the newest cars in the fleet rather than the oldest. I thought Metro might have preferred that arriving travelers see the new cars, rather than the crummy old ones. But Stessel said the reasons were more practical than aesthetic. The new cars were available for the temporary mission and could have been moved back into service if needed. The oldest cars, the 1000 series, are considered the weakest design to sustain crash damage. So they can be used only in the middle of a train set. (They are scheduled to be replaced by the 7000 series rail cars, which begin arriving this year.)