As background, the IIHS has some unflattering things to say about the low beams ("inadequate"). and hints that the automatic high beams are the way to compensate. It's on their web site, which the forum software is not allowing me to mention. They made a bad first impression. The environment was suburban twilight with plenty of streetlights. Twice in a single ten mile trip I manually dimmed it because there was traffic oncoming and I was getting uncomfortable. Searching the forum for "automatic high beams" turned up similar experiences in the Prius V section going back to 2018, which is my model year. The consensus seemed to be that eventually the system will dim the headlights, and nobody reported other drivers acting offended. But still. Are there environments where they work better? Has Toyota offered a software fix? When I was young, and a lot has changed since then, if you thought your vehicles headlights were inadequate you could replace them with aftermarket ones. Is that an option any more? Is the AHB behavior better than it looks? The dimming wasn't happening on my schedule for sure, but is it in a safe range?
2018 is an early generation of the system (TSS-P). Mine is the same year. It does not work well in my opinion. I can usually react faster than the "automatic" mode which is crazy because computers should work almost instantly. Sometimes it doesn't let me turn on the high beams at all. And sometimes it just behaves erratically. The LED low beams on the Prime seem pretty good. I don't think IIHS specifically tested them. They only tested the regular Prius which has different lights. The high beams on the Prime are extremely bright, and I don't want to subject other drivers to that (except in the rare case that they deserve it). There are so many ways they could make it better. I guess federal regulations keep us from having adaptive headlights. Another improvement could be to imperceptibly pulse the vehicles headlights in sync with the camera. For example turn the lights off for 1 millisecond and have the camera save a frame. Anything that goes dark is a reflection, and anything that stays light is an external light source. As long as it's fast enough not to be visible to human eyes, you wouldn't notice it. Has anyone driven a car with TSS 3.0? With a couple generations of improvements does it work better?
our 2024 hycam works exceptionally well. tss2.5 not perfect, but turns the high beams off when you want them occasionally, but always turns them off with oncoming traffic. seems like a sensor issue.
Mine will always eventually turn them off for oncoming traffic, but it takes a second or two. It should be close to instant for me to really trust it. Two seconds is plenty of time to blind the other driver.
I don't know which TSS is in our 2018 c model, but the auto hi beams work great. I mean, I've caught a mistake here and there but most of the time it does what it says on the tin.
It might depend on the roads. Around where I live, winding back roads are the only ones with low enough traffic to use high beams at all. Speed limit is usually 35-55. The automation might work better on a straight highway where oncoming traffic is coming straight at you.
Thanks for all the thoughtful and informative replies. FYI, the IIHS rating was indeed for the Prime, and they said "On the straightaway, visibility was fair on the left side of the road and inadequate on the right side. On curves, visibility was good on both right curves and inadequate on both left curves."
I have reduced my night driving, in part due to senior eye issues, so haven't yet driven my R4P with TSS2.5 much at night yet in conditions where high beams can be used. Infrequently enough to have forgotten how to even set it up correctly during the first part of crossing the mountains last night. It had somehow been switched off since the last use i-don't-know-how-long-ago. But once turned on, it worked very well the rest of the last night's drive.
I made a post a few months ago on how to turn it off on my 2017 Prime (I didn't expect my base trim to have that). Its performance is really poor.
On our ‘22 XLE Nightshade it works great, sensitive enough to handle in town driving with out offending on coming traffic or traffic we approach from the rear.