Some Metro commuters slogging their way around the latest SafeTrack closures in Northern Virginia have questioned why their Metro shuttle buses have been stuck in traffic on Route 1 in Alexandria while adjacent dedicated bus lanes seem to sit mostly empty.

Why can’t the Metro shuttle buses use the Metroway BRT lanes during the SafeTrack closures?

After a frustrating ride on a Metro shuttle bus Wednesday morning, Rep. Don Beyer (D-Va.) added his voice to calls for opening the dedicated bus lanes to more buses. Beyer said it took his bus 50 minutes — more than twice as long as the 20-minute ride he’d expect during the morning rush — to travel four miles between Metro’s Braddock Road and Pentagon City stations. For almost half that time, the bus inched alongside the dedicated Bus Rapid Transit lanes that run seven-tenths of a mile along Route 1 in Alexandria, between Potomac Avenue and East Glebe Road. Meanwhile, he said, he didn’t see any Metroway buses in the BRT lanes.

“That’s hard to justify when people [on a bus stuck in traffic] are looking at lanes that are empty,” Beyer said.

Opening the Metroway lanes to Metro shuttle buses during the surge would help commuters during the SafeTrack rail closures, Beyer said.

“It wouldn’t solve the whole problem, but out of that 50 minutes, it would have cut 15 to 20 minutes off,” Beyer said. “Plus, you’d avoid the senselessness of sitting on a bus stopped in traffic and looking at empty lanes…People [on the bus] were saying ‘Why can’t we drive on that?’ ”

He added, “It’s an obvious question…It gets a little baffling.”

Alexandria and Arlington transportation officials say they’ve been monitoring traffic closely during these past two surges. In addition to local jurisdictions boosting bus service during Surges 3 and 4, they said, Metro added its shuttles and more buses to the Metroway BRT lanes. Surge 3 closed part of the Yellow and Blue lines south of Reagan National Airport to Braddock Road from July 5 to July 11. Surge 4, which started Tuesday, closed the Yellow and Blue Lines north of the airport to Pentagon City. It’s scheduled to end July 18.

Yon Lambert, Alexandria’s transportation director, said officials from Alexandria, Arlington and Metro decided not to add any of the more than 40 additional Metro shuttle buses to the BRT lanes because they would create a bottleneck where the BRT lanes join Route 1 at East Glebe Road, in the congested Potomac Yard area.

The Metro shuttle buses now stuck in rush-hour traffic, he said, would just get stuck at the bottleneck as they tried to leave the BRT lanes. Moreover, he said, the Metro shuttle bus drivers haven’t been trained in how to drive in the Metroway, which has specialized signals at intersections.

“This is an unusual circumstance,” Lambert said of the surge closures. “That number of buses is just not what the transitway was designed to carry.”

Dennis Leach, Arlington’s transportation director, said transit officials also didn’t want the Metro shuttle buses, which provide express service between Metro stations, to get bogged down behind Metroway buses stopping at all their regular stops.

While Arlington officials are seeing “some congestion” during the morning and evening peak during the surges, Leach said, the traffic impacts haven’t been extraordinary.

“We haven’t seen significant delays in Arlington,” Leach said, “and we have very extensive camera coverage.”

Beyer said he doesn’t buy the argument that the shuttle buses would create a bottleneck as they left the Metroway lanes to join Route 1. He said a traffic officer could direct traffic at the intersection to move the buses back into the regular lanes more quickly. Doing that, he said, would move more people more efficiently than having buses sit in traffic. It’s worth a try, he said.

“I hope Metro is constantly thinking of ways to be creative to minimize the impact on people” during the surges, Beyer said.