Change the World

I have noticed that there are fewer cars behind me on my morning drive. I don't mean fewer tailgaters; I mean fewer cars at all. More and more often, I find big stretches of my drive with no one behind me. This morning, for half of my longest 30 m.p.h. stretch, the road was empty. For the rest of the drive, I generally had one person behind me.

Let's assume for a minute that I am somehow the cause of this (I'm sure I'm not, but I can still dream). Are cars realizing that this route is slow and picking alternate routes? Are cars slowing down so fewer are catching up to be behind me?

In reality, I can't imagine I am making that much of a difference (if any at all), but I was thinking, how many cars driving the speed limit on the same set of roads would it take to make a significant change? I could imagine that if someone had a similar schedule and ended up behind me a lot, that person might choose to do something different (drive more slowly, take an alternative route, enroll in an anger management program...), but my driving wouldn't have that big an impact on that many people (if any). Now, imagine there were 2 or 3 or 10 cars that drove that route around the same time at the speed limit. How many would it take before the route got a reputation for being slow?