yes. absolutely trucks go 75-80 on I95. More. And on US50. And on 495. And on 695. I66, I97, 270, I70, the list goes on. The truck philosophy is to get between New Jersy/Philly and Richmond ASAP because the probability of getting snarled at DC is so high, and the effects stretch to Richmond and Baltimore.

IMO this is substantially because unlike, say, Chicago or Dallas or LA or NY, DC itself is proportionally not an end-point for long-haul commerce traffic (pop <500K), yet almost all Eastern commerce needs to flow past it. It sits right on the middle of the Eastern artery like a piece of plaque in your aorta. Add to that one of the 1st Beltways ever built (read: worse for the wear, and lacking some later innovations) and a drawbrigde on 95.

Toss in on top of that the fact that we here are basically in as much of a hurry as New Yorkers (native NY, so I can speak to that), but lacking some stoicism of a Noo Yawka.