I believe there have been studies that indicate traffic accidents on freeways increase as the speed delta between vehicles increases. My opinion (biased, obvio

I believe there have been studies that indicate traffic accidents on freeways increase as the speed delta between vehicles increases. My opinion (biased, obviously) is that the people who choose to drive significantly below the speed limit are more of an issue than those who choose to drive above it. Someone driving over the speed limit is going to be monitoring the traffic ahead of them. Those are the people they are most likely to interact with. Someone driving exceptionally slowly is much less likely to be monitoring the traffic behind them adequately enough to know when someone is approaching them rapidly from behind. Further, the amount in excess of the speed limit that the vast majority of people would be willing to drive is a fairly small delta (10, maybe 15mph max). The amount below the speed limit someone may choose to drive is much larger, mostly by definition of it being any value from zero to the speed limit. A habit I picked up a few years ago thanks to seeing others doing so is to put on my 4-way flasher hazard lights if I'm driving significantly below the speed limit (usually due to snow or super heavy rain). It helps alert people that "hey, this person is going slower than you probably expect them to be, so pay attention"