Sounds good to me!
The current two Piedmonts a day require two sets with one set for 73-74 and one for 75-76. If you wanted to schedule, let's say 77 and 78 without requiring a third set you can have 77 leave RGH around 7-7:30pm and arrive in CLT around 10:30-11pm. But then 78 would have to get back to RGH at least 1-2 hours before the 75 (11:45am) and the 80 is right around that time. Ideally you'd have a nighttime northbound 78 in the 7-11pm range but you'd need a new set or more creative set switching.
If you don't mind needing a 3rd set but would rather schedule for transfer opportunities,
You want 78 to arrive in RGH in enough time to catch the SS southbound (9:01pm). 8:36pm (76) seems tight for me. How about 3:30pm out of CLT arriving in RGH around 7pm? So 78 would be between 74 and 76 (or they renumber them). You want 77 to leave RGH after 8:45am but late enough so they guarantee the connection from the northbound SS. 11:45am (75) seems a bit late a wait if the 98 is on time. I don't know if scheduling a 10:45am or 11am departure right before the 11:45am is worth it (but should get back to CLT to allow to return at 3:30pm from there).
Ideally you could schedule a trip to connect RGH to either Greensboro/CLT to the Crescent but their times are in the graveyard shift.
The OTP is good enough on the Piedmont that 76 is a guaranteed connection to 91. I have boarded 91 at Raleigh many times, most of which 91 ended up waiting outside the station for 76 to depart to the yard. Another thing to consider is that the connection can be made at Cary, making it 65 minutes which is more than enough for a corridor train.
Ideally, I would like to see the next southbound Piedmont leave Raleigh around 8/8:30, arriving Charlotte between 11 and midnight. This would allow people to work to 5 or 6 in Raleigh and still make a same-day train, in addition to providing a shorter connection time to the Crescent. The connection at Greensboro would be from around 10 PM to 12:22 AM, which is really not much worse than the Pennsylvanian/CL. In fact, the connecting time itself is shorter. Few people want to board a train at 2:45 AM (Charlotte's southbound Crescent departure time) however, so it would be important that the official connecting station is changed from Charlotte to Greensboro. I have connected at both in the past, and Greensboro is also a much nicer station.
In the future, this corridor could probably support three additional trains than the present (six total), with one between 73 and 75 and one between 75 and 79 in addition to the later night depature. The same changes could be made to northbound service, with one train between 80 and 74, one between 74 and 76, and one after 76. I also believe the late train should be the first one to be implemented northbound. Unfortunately, these new trains would do nothing to improve connections from the northbound Crescent, but even with connecting passengers I doubt there is enough demand for a train departing Charlotte before 6 AM.
Another possibility I would look into if I was North Carolina is another train or two to the NEC. Although both Raleigh and Charlotte currently have two, they are scheduled very close together in Raleigh and one of Charlotte's trains is in the middle of the night. A late northbound and early southbound train could be popular. The train would likely arrive/depart New York in the middle of the night, but the sheer size of the city and the slightly better calling times at Philadelphia lead me to believe the train should still be run up the NEC. This could be 74 northbound but the southbound would likely require a currently unscheduled train between 75 and 79. This train could also potentially be combined with 65/66/67, providing direct servicd to Boston. Another idea could be an overnight train between Raleigh and Washington. It could be a continuation of 73 southbound and a potential new circa 8-9 PM departure from Charlotte.
Either train could also be extended to Atlanta if South Carolina and Georgia change politically, with one train providing same-day service as far as Philadelphia from Atlanta and the other providing direct service from Atlanta to Raleigh and Richmond.
