Hopefully we all have these useful safety features already. Seat belts, Airbags, antilock brakes (ABS), traction control, electronic stability control (ESC).
Backup cameras can vary. On our Toyota’s they were a nice addition, though we always look with our own eyes too. To my surprise, the Subaru backup camera lens gets dirty easily, I have to wipe it clean sometimes. Not so with Toyotas we’ve owned. Inferior aero vs Toyota? Model specific probably.
The OP was more likely asking about the driver assist features below. The systems vary by carmaker, using different technology, some are significantly better than others, and of course they all use different acronyms. None are perfect, many won’t work on ice and snow or even in a downpour (rain) or if lane markings aren’t good.
There won’t be a consensus anyway, but my take...
My favorites:
• Blind-spot warning (BSW):*Visual and/or audible notification of vehicle in blind spot. The system may provide an additional warning if you use your turn signal when there is a car next to you in another lane. I like blind spot warning because it tells me when someone is in my blind spot without me straining to look. It’s a light on the right and left mirrors that glow yellow if someone is there. What’s the downside?
• Rear cross-traffic warning:*Visual, audible, or haptic notification of object or vehicle out of rear camera range, but could be moving into it. I like rear cross traffic warning because there are times when you’re backing out and simply can’t see because the [-]monster SUV/pickup[/-] vehicle next to you is blocking your view. Instead of creeping out and hoping no one has to swerve to miss you while you strain to see if anyone is coming, the warning tells you to wait. What’s the downside?
Honorable mentions?:
• Rear automatic emergency braking (Rear AEB):*Brakes are automatically applied to prevent backing into something behind the vehicle. This could be triggered by the rear cross-traffic system, or other sensors on the vehicle. Rear emergency braking is nice, but the warnings above will most likely prompt you to stop before the car brakes. The only time rear emergency braking is useful to me is when there is a low post or wall you can’t see at all, then it’s handy.
• Adaptive cruise control: *Adaptive cruise uses lasers, radar, cameras, or a combination of these systems to keep a constant distance between you and the car ahead, automatically maintaining a safe following distance. If highway traffic slows, some systems will bring the car to a complete stop and automatically come back to speed when traffic gets going again, allowing the driver to do little more than pay attention and steer. Adaptive cruise control is a mixed bag to me. Sure it’s nice that it automatically slows to match the car ahead. But if you want to go 60 mph and you’re approaching a car doing 50 mph, do you want to go 50 mph from then on? With adaptive cruise control, you learn to change lanes well before the cars system “sees” the slow moving car ahead. You could do that yourself with the old non-adaptive cruise control.
50/50:
• Lane-departure warning (LDW):*Visual, audible, or haptic warning to alert the driver when they are crossing lane markings. Some people find this helpful while others find it annoying, and it’s unreliable anyway. If you tend to wander (why?) it’ll warn you so you can correct. But if you’re changing lanes with no one anywhere nearby - it’ll beep and flash every time you cross a lane marking unless you have your turn signal on every time. So you have to signal every time, accept warnings when they’re not needed, or disable LDW. And these systems rely on painted lane markings, if they’re faint or missing, LDW won’t work. Where I live lane markers are kinda hit and miss off highways.
• Forward-collision warning (FCW):*Visual and/or audible warning intended alert the driver and prevent a collision. Not a bad thing, but not perfect either. A system that warns you soon enough to act will sometimes beep and flash unnecessarily, mine does if a car slows to turn ahead of me and I get close for an instant just before the car ahead clears. If the system was less sensitive, it would be too late in a real emergency. Catch-22? See next feature.
• Steering responsive headlights. My car has them, the difference is negligible to me. I don't even notice the beam moving unless I consciously look for it.
My second least favorite:
• Automatic emergency braking (AEB):*Brakes are automatically applied to prevent a collision or reduce collision speed. If the FCW warning above didn’t prompt you to brake yourself, why are you so distracted? These systems aren’t magic, they won’t prevent a collision if there’s no warning at all, e.g. if you’re going 60 mph and a car unexpectedly crosses in front of you, AEB might brake a little sooner than you would, but it won’t prevent a collision. Depends on the car/system but some will only prevent a collision at low speed like 35 mph and below while others may work up to 60-70 mph. Do your homework, these systems aren’t all equal between carmakers.
My least favorite:
• Lane-keeping assist (LKA):*Automatic corrective steering input or braking provided by the vehicle when crossing lane markings. Lane departure warning should prompt you to correct yourself before the car has to. Lane keeping will only correct a couple of times before a stern warning and/or shutting off because you’re clearly not paying attention. And again, these systems rely on painted lane markings, if they’re faint or missing, LDW and LKA won’t work. Snow, ice and heavy rain are also trouble for LDW and LKA.
Other:
• Lane-centering assist: *Continuous active steering to stay in between lanes (active steer, autosteer, etc.). I haven’t experienced this, it’s a precursor to self-driving cars. Available on Tesla and some new Cadillacs and Lexus that I know of.
I just bought a new car with everything above except lane centering assist. And I like the driver assist features for the most part, you learn when and how to use them. Some are helpful at all times, some are selectively useful. OTOH, the dealer told me lots of buyers come back within two weeks of taking delivery of their new car and ask ‘how do I turn off all these *#&$ safety doo dads?’ FWIW.
