Okay, let's do the math

(I just want to say here that 1: it's entirely possible I'll make an error here, I'm far from perfect and I'll own that, and 2: I recognize my last remark was snide and I was kinda pissed, and there's no real reason to be, so I'm sorry for my tone, and I'm making the conscious decision here to not respond heated but just discussing about facts as I can see them)

I'll go with 60 mph for this since that's what I find commonly tested (people seem to like 0-60, so 60-0 I guess makes sense to them)

Since the general rule is to maintain 2 or 3 seconds of following distance (depending on who you ask), let's see how far that is.

60 miles per hour, 60 minutes per hour, and 60 seconds per minute, so 60 / 60 / 60 = 0.0166 (continuous) miles per second. Multiply that by 5280 to get the number of feet per second: 88.

So, for 2 seconds, you'll have 176 feet between you and the car in front of you. At three seconds, that's 264 feet.

Quickly switching to 70 and those numbers become 102.66 (cont) per second, 205.33 (cont) for 2 seconds, and 308 for 3 seconds.

Just for comparison, I looked up the tested stopping distance for my car and 60-0 is about 120 feet (actually a little less than that). Which is good, but even your average (which I'm not finding a source that verifies that, but we'll assume it's correct) would put the stop at 280 feet for 70 mph, which is under the 3 second distance at that speed.

If you can see any flaws in my logic or math, I'd love to hear it. But I will add that I typically maintain between 2 and 3 seconds, and I'm rarely cut off. If anything, it makes me less likely to be cut off since there's room for someone to get in allowing traffic to move between lanes more easily, and I just adjust my distance in response.

I don't know what drivers are like there, but we have some pretty aggressive drivers here, and other than the occasional asshole tailgating me (which I slow down for to give them more chance to respond if I need to stop suddenly... They don't like that, but tough, I'm not risking my neck for their impatience), I don't really have any problems with it.

If you can't stop by the end of your current vision, you're going to fast around a corner... By the same token, if you can't stop by the tail end of the vehicle in front of you, you're driving too close to them. For the most part, we don't really follow that, but at the very least, if we're not in a middle lane and there's a shoulder, we should at least be able to dodge them if needed.

My point is, just about any accident involving your car hitting another going forward, barring something like mechanical failure or the person behind you hitting you into them, is likely avoidable through more defensive driving and greater (but still reasonable) following distances.

As a side note, I spent several months refusing to drive over 55 mph (in the far right lane at all times, except for the like 2 times I actually had to pass someone) and did not have any issues from it. In fact, it had very little impact on my time to destination, and made the commute smoother since I wasn't having to vary my speed to keep pace with traffic. It also made the drive less stressful and used way less gas. This is in spite of the "common wisdom" I seemed to get from people saying that driving that slowly was far more dangerous.

Are you seriously driving at speeds of 70 mph in dense urban environments....?

Because, speaking as someone who has lived in many dense urban environments, that's insane.

The only time you should reach those speeds is on the freeway, in which case, there's no reason not to maintain safe distances, when at those speeds.