Congrats to NE2 (again, again) for winning the March 20 trivia night! Of course, that means he hosts next time. In the meantime, come chat with us!
Not really. VDOT has a lot of power to set speed limits...they just don't use it very often.
The only thing the General Assembly has done is set what the maximum speed limit could be...70 on the Interstates and limited-access roads, 60 MPH on 29, 58, 360, 460, and part of 17, and 55 MPH otherwise. As long as it doesn't exceed that maximum, VDOT (through the CTB) has the authority to set the speed limit to whatever they want, subject to a traffic and engineering study.
Which is what I think is a very poor way of handling the issue and what I consider to be giving VDOT not enough discretion. A road like VA-28 north of I-66, for example, is better than many of the Interstates in Virginia yet is limited to 55 mph under the current system because the portion from about Sully Plantation south doesn't qualify for a higher limit. That's dumb, too; there's no reason why a road can't be posted higher in one place where it's a better and wider road, except for the General Assembly wanting to keep control.