I just got back from a trip to Williamsburg, Virginia from Fairfax, Virginia.
I am not a speeder. I have learned from the past; trying to be "first" can lead to anxiety and pressure. On I-495(DC area), I-95, I-295 (Richmond area) and I-64; I found that the speed limits mean little to most. Based on experience, I pegged my speed control at or about 10mph over the "posted" on I-495 and I-95 - and was passed left and right. Not a cop to be seen.
Because of entrance ramp traffic, I found myself in congested areas being in the center lane on 495 and 95, but being at or about 10mph over the limit was not goo enough for many. The right lane was too slow for even my rate of travel in some areas. That did not prevent me from being tailgated, or cut off in in "illegal" lane changes.
On 295 and 64, where the Virginia State Police seem to be able to have a greater presence; the speed traveled by most was right around 5mph over the limit. On my return trip, I took US17, just west of Williamsburg. What a great ride! No truckers riding your bumper. Everyone seemed to be pegged at about 5mph over the limit. And those that were above, well they got a ticket to the "State Ball". All in all a relaxing trip back.
The problem I have with some of the posts here, is that there seems to be a need for speed mentality. Sure I have done stupid things with speed behind the wheel of a car. But they were in short bursts in my youth.
In many urban areas, there are not enough police or places for the police to pull over speeders today. When I got my license, it was underdstood that up to 5mph over the limit was OK. Today it seems to around 10mph over the limit. But on some roads it seems to be 15mph over the limit.
The issue is, that for some of us a speeding ticket is a major hit on the wallet and/or insurance. Whether 5mph, or 15mph over the limit. But we are forced to "break the law" on speed limits because of an increasing majority that feel speed limits on certain roads are ill placed. Or maybe because they feel that they need to exercise their souped up cars.
In the end, if you want to find out how fast your car can go; go to a track. Safer for you, and the safer for the rest of us.