This does happen, but I find it doesn't result in me getting to my destination any slower.
If someone merges close in front of me, I reduce my speed by 5 mph or so for as long as I need, probably usually around 10-20 seconds, until there's an adequate gap again. Often someone will pull into that gap within a few mins, and I do the same thing. Overall it reduces my average speed by an imperceptible amount. It might add up to a couple minutes over a several hour journey, but I take that as worth it for being less likely to rear end someone.
Additionally, it really only happens in dense traffic when in the outside lane to exit the highway. When you're in the fastest moving lane and keeping up with traffic, few drivers are going to over/undertake you just to get into the gap. More typically they'll overtake the car in front of you too so it's not a problem.
Admittedly most of my driving is in UK and NW Europe rather than the US. US drivers seem a lot more suicidal and US highways tend to be less predictable by design.
If someone merges close in front of me, I reduce my speed by 5 mph or so for as long as I need, probably usually around 10-20 seconds, until there's an adequate gap again. Often someone will pull into that gap within a few mins, and I do the same thing. Overall it reduces my average speed by an imperceptible amount. It might add up to a couple minutes over a several hour journey, but I take that as worth it for being less likely to rear end someone.
Additionally, it really only happens in dense traffic when in the outside lane to exit the highway. When you're in the fastest moving lane and keeping up with traffic, few drivers are going to over/undertake you just to get into the gap. More typically they'll overtake the car in front of you too so it's not a problem.
Admittedly most of my driving is in UK and NW Europe rather than the US. US drivers seem a lot more suicidal and US highways tend to be less predictable by design.