Like ALS, there is a perceived rate of progress at which I feel comfortable. That rate depends on the vehicle. If I were to drive with the speedometer obscured so that that reference point were not available, I'd end up at about 2000 rpm in my diesels (as that point in the sound and vibration harmonics are low) which corresponds with about 62 mph in 5th. If I were driving 70 and couldn't see the speedometer, I'd eventually find my speed dropping to the low 60's. In congested reduced speed limit areas I invariable tend to creep up from posted 50~55 to that same low 60's.
My Sonett is much lower stance and higher revving, but it's comfort level is about 3000 rpm, about 53 mph. There is another sweet spot about 4000 which returns about 70 mph. I'll seldom catch myself driving that car in the 60's. When I need to take the Odyssey (hate the seats!) I'm higher from the road and find myself near 70 in that.
My problem comes when I get onto secondary roads posted at 35~50 mph. I invariably creep up to the same speed until I catch myself.
Or in snow storms when drivers insist on being in the half-fast lane at 35 mph while no-one is in the right or left. Then I'm at low 60's over in the left.
The Boston area has similar right lane drops and short on-ramp merge lanes as the G.T.O. area, and also has number of miles on interstate in which the disabled vehicle lane is also a legal travel lane, yet with me at 55~65 mph, with prevailing traffic at 75+, I'm not an impediment in Boston or Toronto (or Atlanta, or DC, or Dallas.)
Drive right, pass left. Don't be a half-assed driver by loitering in the half-fast lane.