^ I-81 through basically the whole state (exceptions being Christiansburg thru Roanoke, Staunton, Harrisonburg, and Strasburg) is posted at 70 mph, in a lot of areas with 60 mph curves and short acceleration / deceleration lanes.
I’m not opposed to, as I would see it pointless to have to hold 65 mph in a lot of those areas on the straightaways, but VDOT has been lenient in a few areas with those higher speeds.
As far as traffic density, wouldn’t that argument apply for the entire DC-Richmond corridor then? The stretch of I-95 between Ashland and Fredericksburg has high volumes of traffic and frequent congestion paired with a 70 mph speed limit.
Not I-95, but I-64 east of Richmond is often plagued with congestion, and a roughly 40 mile portion between Bottoms Bridge and Williamsburg is posted at 70 mph.
VDOT seemed selectively with the 70 mph limit initially, but then extended it to basically all rural interstate highway segments in the state, even in some questionable areas.
As far as I-95 north of Fredericksburg, wouldn’t, at the very least, the reversible HO/T lanes south of Woodbridge (not the original 1970s portion, the newer part built with the Express Lanes project in the last decade), be designed well enough for 70 mph?
Additionally, wasn’t all of I-95 between Ashland and Triangle widened to six lanes and to the same design specification in the 1980s? What was different about the design south of Fredericksburg than north of Fredericksburg that warrants a speed difference?