Rock n Roll DC Marathon race report:
I've done this full twice before and hadn't planned on doing it again. This is because most of the support has been for the concurrent half, and after the half marathoners finish, the second half of the full is pretty dull and goes through some less-than-scenic parts of DC. The organizers have in the past given nice running jackets to full marathon finishers, and my son was jealous of the two I'd received, so he persuaded me to run it with him in 2018 so he could get his own. Of course, a few weeks before the race, we learned that the Rock and Roll group had discontinued running jackets for full marathon finishers in 2018, so ... yeah.

Anyway . . .
Our group consisted of me, my 18yo son Sam, and Ali, a former XC high school teammate of his. Sam had always been a much stronger XC runner than Ali when they both raced, but she'd also trained much more for this full than Sam, who'd barely trained at all. Because this was Ali's first full, we agreed they'd start together with the 4:25 pace group, and see how the race unfolded. Knowing that Sam was running with a pace group, I picked the 3:40 pace group for this race. I was mostly looking to get some training miles, since I wasn't looking to race this event, and I wanted some company on the course.
Beginning last year, the half and full had different start times, with the full runners starting 1.5 hours earlier. Being that there were only about 2000 of us, and 10000+ had registered for the half, the start area was (relatively) deserted when we arrived, which was nice. Gear check was a breeze, and there was absolutely no wait for portapotties - just walk right up! I could get used to that!

There were 20+ corrals marked off stretching nearly three city blocks, but we full marathoners only used 5 of them, and they weren't really enforced anyway. The race itself was pretty uneventful - the course was similar to years past, and the series of hills between miles 22-24 again got me, causing me to lose touch with the 3:40 group, which had dwindled from about 15 strong to 3-4 runners following the pacer. The pacer himself was from a local Maryland running club, and he was also going to run a full the next day (Sunday) too as part of his training for a 100 miler in April!

I never caught back to the 3:40 group, but kept them close and finished with a 3:40:19. I then found my wife and waited for Sam and Ali. We saw Ali first, finishing alone. She saw us along the final stretch and flashed a big smile as she passed. She got 4:25, a great result for a first marathon. More importantly, she enjoyed the experience and wanted to do another!

Sam came in at 4:33, an improvement on his time at WDW in January. He was pretty beat, as you'd expect based on his (lack of) training. Still, he finished and was happy to have run with Ali until mile 20, when she pulled away. We then met up with a few more running friends finishing the half, and headed home. Quick review of the RnR DC race: A much better half than a full. If you want to run a full marathon in or around the Nation's Capital, run Marine Corps instead.
No real tips, just that it’s OK to be slightly overwhelmed! Just take it all in, follow the crowd, get where you need to be early so you don’t stress and then run your race that you trained for!
Yeah, it’s a lot of people but the cool thing is they all have the same goal in common as you - finish the race!
@SarahDisney
Great advice from Keels! I'd also add that 99% of the runners I've met are great people, and happy to chat before, during, and after a race. There's a lot of camaraderie in the shared suffering of a race, and I've always gotten lots of encouragement from fellow runners going up tough hills, etc. Just try to enjoy the experience and if you see someone struggling, share a few encouraging words - it'll probably be as helpful to you as it is to them. Best of luck on your race!