Used mine in VA for over two years now with one. I’ve only heard of one guy actually getting a ticket and it’s still way less than a speeding ticket.
It’ll be 8.5-9 at best if you’re doing it in the day, more like 10-11 if you take 95 at the wrong time.
If you want an easy 9-9.25hr drive almost every time, do 87 to 287 to 78 to 83 to 695 to 95, but you still cant hit Baltimore and DC at the wrong time. 95 straight down is a nightmare during the day, only use at night.
Dont be near DC (especially just south of it) from 5-7pm. Always take 495N/S around it, never through it like your GPS wants.
Just my $.02. I’ve been doing that trip every couple weeks for 6 years now.