[schreiaj]

It’s also difficult to determine if someone is speeding from data.

For example the road I live off of according to the speed limit the car thinks goes from 40 to 65 to 25 to 65 to 40 in about a 4 mile span. Spoiler it does not. It is 40 the whole way. But according to the car I am either going 25 under, 15 over, or exactly the right speed.

(And the 65 section in the middle? Blind corner. Idk where it’s getting its data but it is very very wrong)

[everforward]

Indeed, the usual garbage in garbage out issue.

Iirc, though, I think I read something about this and they were more interested in average speed (regardless of posted speed), and the rate/frequency of acceleration/deceleration (especially deceleration).

The idea being that speed increases accident severity, regardless of posted speeds. Rapid deceleration is indicative of reacting late to something you should have seen and responded to earlier (eg following too closely and having to slam the brakes, not seeing someone merging, not slowing down for a yellow light, etc).

Basically that a safe driver would have a fairly smooth acceleration/deceleration profile because they're aware of what's happening around them and pre-plan accordingly. If someone wants to merge in, give them room and then back up enough that you can brake slowly if something happens.

I still don't want to be tracked, but their metrics seemed sane at first pass.

[volkl48]

As someone in the Northeast US: Many of our highways were designed 80+ years ago, and do not have appropriate acceleration/deceleration lanes.

The terrible drivers are often those with the most timid inputs, especially with regards to acceleration. It is perfectly normal here to need to merge into heavy, 60mph+ traffic from a dead stop, or to need to quickly match speed and identify an appropriate merge spot to not wind up stuck at the end of a ramp.

And it's not like they sit there for 15 minutes waiting for some exceptionally large gap to match their acceleration habits - that would be very annoying to other drivers, but theoretically "safe". They enter in the same length gap as someone that actually uses their gas pedal - but rely on oncoming traffic to hit their brakes/evade, as they fail to get up to speed quickly enough for the small gap they've entered in.

-----

Hard braking is something with fewer reasons it should happen regularly - but I'm still reminded of the usual adage about metrics. Do you really want people to be mentally reluctant to hit their brakes as hard because of the insurance hit? That seems like a recipe for increasing decision time and accidents.

[schreiaj]

Maybe if the only thing you're reacting to is other vehicles or the road. The number of times I have to slam on my brakes on that particular road because of animals running into the road is way too high. And no, not always deer. I've come around curves and just had someone's dog sitting in the middle of the road on multiple occasions because for some reason people think it's totally safe to just let their dogs roam.

[bruckie]

That indicates real increased risk, though, compared to someone who drives in places where animals are less likely to be in the road.

Insurers aren't trying to determine how good of a driver you are (conditional probability of you being in a collision given conditions). They're trying to determine how likely it is that you're going to be involved in a collision that results in a claim (unconditional probability of you being in a collision). If you frequently drive through deer infested forests, it seems reasonable that your insurer is going to expect more claims compared to someone who doesn't do that.

It's similar to how driving late at night results in higher premiums. You can be the same good driver at night and during the day, but if you're frequently driving at 3 a.m., you're a higher risk.