Decided to take a chance and save time, I went about 8 miles down the 101 (nor-cal) today. It seem to cruise just fine @ 55 MPH, the tach was showing about 7400 RPM. I did see 60 + once in a while. Got off before I saw any cops, didn't want to push my luck !
55-60 is perfectly legal on all interstates in Texas. The law only says you can't impede the flow of traffic but there is no engine size or speed requirement. The Grom is faster than some trucks plus you can just stay in the right lane and you won't be impeding anyone. They can just pass.