The transit authority unveiled a weekend maintenance schedule today that reflects its new approach to the track work program. Riders who have grown used to having the weekend trains share a single track to get around work zones will find that Metro more often will be completely shutting down sections of lines and using shuttle buses to carry passengers around the disruptions.

This new plan does not eliminate single-tracking. You can see the new schedule for major track work here. It shows the impact of major track planned through June 2012.

The schedule starts this coming weekend. It shows that buses will replace trains between East Falls Church and West Falls Church, and also shows what work will be underway: “Switch installation for Dulles extension; tie replacement work; replacement of rail.”

However, in a separate announcement, Metro also has said it plans to have trains share single tracks through weekend work zones on the Red, Blue and Yellow lines. (See the full list of this weekend’s work.)

That means four of the five lines are disrupted in some way. If that’s a typical pattern for the future — a combination of single-tracking and complete shutdowns in certain sections — many weekend riders won’t notice how they’re better off.

Metro says in its announcement that it will still use single-tracking during work on smaller projects on weekends and during midday and late-night hours on weekdays.

The new schedule provides a list of what Metro considers to be “major weekend track work,” and that will be helpful, if not complete. This level of advance information was not previously available to riders.

The complete shutdown of a line segment is not in itself a new approach. Metro has done this plenty of times in the past few years, especially on holiday weekends, to complete major track work, such as switch replacements.

That experience validates this more aggressive approach to scheduling weekend shutdowns. When Metro has a chance to schedule a bus bridge between stations well in advance of the work date, the system works pretty well for both riders and repair crews.

The workers get complete access to the tracks. Not only is that safer than single-tracking, but it also allows Metro to schedule a greater variety of maintenance work in one track segment.

For riders, Metro can schedule what’s generally been a sufficient number of buses to meet each train. This planned outage in rail service is usually much less stressful for riders than the emergencies in which Metro must quickly organize a bunch of buses to handle the confused and angry crowds emerging from a station where a problem suddenly occurred.

Still, I don’t want to minimize the impact of the scheduled shutdowns: It means that on most upcoming weekends, riders on one line or another will encounter a zone where they have to get out of their trains, walk out of the station into the heat, cold, rain or snow to board a bus that will have to wind its way along local streets to get them to the next rail station where service is available.

What’s to like

The new schedule for major work gives riders the best information they’ve ever had for planning weekend trips.

Metro says that the shutdowns have less effect on a line than single-tracking, during which trains must wait their turn at the start of the single-tracking zone, leading to delays along the entire line. Cutting track capacity like that also may require using fewer trains on the entire line.

So outside of the zone where a complete shutdown occurs and the shuttle buses are in use, service on that line should be close to normal. (Metro reported few problems or complaints when it employed this system over the Memorial Day weekend, despite the large number of visitors and the many events.)

Because so much maintenance can get done when there’s extra space available, the overall maintenance timetable gets speeded up under the new approach. Deputy General Manager Dave Kubicek points out this highlight: The new approach will allow Metro to complete the Red Line track circuit replacements, recommended by the National Transportation Safety Board, about 18 months earlier than could have been done under single-tracking. That means they’ll be done by this time next year, rather than in late 2013.

The track circuit replacements are one of the things that must be done before Metro can return the trains to automatic, rather than manual, control.

If there’s a weekend shutdown scheduled for a portion of any line, there won’t be single-tracking on the rest of that line for that weekend.