A summer of misery could follow this springtime of discontent for commuters who pass through Pennsylvania Station in Manhattan, judging by Amtrak’s preliminary plan for extensive track repairs at the station.

The plan, a copy of which was obtained by The New York Times, calls for the closing of tracks for two long stretches that would last for nearly three weeks in July and almost the entire month of August. Amtrak has shared the plan with the two commuter railroads with which it shares Penn Station: New Jersey Transit and the Long Island Rail Road.

Officials of the three railroads are meeting this week to devise a final schedule for the work, but there is no doubt that travel will be disrupted. Penn Station is the busiest rail terminal in North America, and New Jersey Transit and the Long Island Rail Road are two of the three busiest railroads in the United States.

The plan presented by Amtrak outlined 21 repairs and described their locations. But it did not explain how the work would affect train schedules during the track closings. The work plan appeared to indicate that at least two tracks at a time would be closed off during the periods in July and August.