Why three timetables?

[DowneasterPassenger]

I'm wondering why the NEC has three separate timetables:

Northeast Corridor 1New York - Washington Effective August 9, 2010

New York - Philadelphia - Baltimore - Washington Northeast

South

Northeast Corridor 2

Boston / Springfield - Washington Effective August 30, 2010

Boston / Springfield - New Haven - New York - Philadelphia - Washington Northeast

South

Northeast Corridor 3

Boston - Lynchburg / Virginia Beach Effective July 20, 2010

Boston - New York - Washington, DC - Charlottesville - Lynchburg - Richmond - Newport News - Virginia Beach

I haven't studied them in detail, but is there overlap between them?

If my travel is primarily between Boston and Philadelphia, should I use #2 or #3 or both?

 

[NS]

Use #2 for PHL-BOS. They are split to improve readability.

1 is for trains operating from NY-WAS

2 is for trains operating from BOS-WAS

3 is for trains operating from BOS-Virginia

 

[the_traveler]

As said, because there are so many trains running on the NEC, they are split into 3 schedules to make it easier to read. Use #2 for anything starting or ending between NYP and BOS.