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Hard-braking events as indicators of road segment crash risk

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Re: Hard-braking events as indicators of road segment crash risk

#531

Post by shepherdjerred »

cucumber3732842 wrote: post #464
mschuster91 wrote: post #439

Earlier quoted context omitted.

Operate like they did before they had access to surveillance technology that would have made Gestapo and Stasi blush

This. If you're nearly "perfectly" pricing risk on an individual level then you defeat the point of insurance which is to pool risk. If my hypothetical cost over an N decade period is within a fraction of a percent of payouts in that time what do I gain by paying for insurance other than creating a principal-agent problem?

You’re mad the insurance companies are charging you what you owe? You do have the option to self-insure.

Re: Hard-braking events as indicators of road segment crash risk

#532

Post by throw0101a »

Someone1234 wrote: post #28

This type of research is highly valuable but too rare; this is generally because of how we view Road Accidents at a core level: - Road Accidents: "A driver caused this, let's determine who, and find them at fault." - With Air Accidents: "The system caused this, let's determine which elements came together that ultimately lead to this event." The first is essentially simplifying a complex series of events into somethi…

> This type of research is highly valuable but too rare; this is generally because of how we view Road Accidents at a core level:

"Crash" not "accident":

* https://crashnotaccident.com

Re: Hard-braking events as indicators of road segment crash risk

#533

Post by Spooky23 »

maerF0x0 wrote: post #504
Spooky23 wrote: post #500

Earlier quoted context omitted.

You’re the problem because of the way you are thinking. You don’t own the asphalt in front of you. You’re angry because in your mind you do, and you feel righteous about it. That’s why you are casting a moral judgement about them. The most efficient throughput of the road system is not for people to “politely” queue up for 5 miles. People should be utilizing the rod and merging in an orderly manner. By adopting some…

> You don’t own the asphalt in front of you. Correct, but you _need_ the asphalt in front of you for both safe driving and also to avoid cascading hard braking events. I also don't own the asphalt under me or behind me too, so it's kinda a silly statement tbh. This youtube talks about it: https://www.youtube.com/watch?v=iHzzSao6ypE

You do, but if you leave so much that 20 cars are pulling in front of you, you’ve either driving too slow or misjudged and left unnecessary space. At 15-20 mph traffic speeds, you need 8-20 feet. Ideally, cars in a multiple lane to one lane exit scenario should be zipper merging when congestion reduces speeds. Engineers model this behavior and try to design roads to encourage it.

If you do that and get angry when people change lanes in front of you, you have consciously or subconsciously decided you own that 20 foot gap. That reaction impairs judgement and causes accidents.

Re: Hard-braking events as indicators of road segment crash risk

#534

Post by array_key_first »

alt227 wrote: post #460
OneOffAsk wrote: post #140

Aim to make the road laminar. Every time you hard brake, you're causing the milk jug to glug, making a ripple of entropy as momentum turns to heat from your brakes and those behind you, sometimes in perpetuity. I learned this while doing a 1.5hr daily commute in a Subaru with a clapped out manual transmission. I wanted to conserve energy shifting, but realized I was now participating in large choreographed dance of "…

IMO there is nothing worse than drivers on highways who think that by leaving bigger gaps and slowing less rapidly they are 'smoothing' out the traffic and helping the whole road run better. You are not, you are just making the whole road run slower and taking up more space for yourself on a crowded road.

This is untrue, there have been studies done that discovered the primary cause of traffic is following too close. Following further away really does reduce the amount of traffic. It seems unintuitive, but consider: every time you brake, the person behind you has to brake a teensy bit longer. And then the person behind them, and behind them. That little bit of extra time accumulated quickly and grinds the highway to a halt.

Re: Hard-braking events as indicators of road segment crash risk

#535

Post by fluidcruft »

maerF0x0 wrote: post #219
Sohcahtoa82 wrote: post #213

Earlier quoted context omitted.

> vehicle changes lanes in front of you; I will never understand why this is so rage-inducing for people. Changing lanes is a necessary part of navigating, even during busy traffic. People on an on-ramp will need to get in front of somebody . People needing to move back to the right because their exist is coming up will need to get in front of somebody . Your lane is not a birth right. Let people merge. > you slow do…

It's frustrating because someone is taking your safety buffer as their opportunity to travel faster. And it results in you having to travel slower and slower to maintain the gap that is constantly consumed, tragedy of the commons style, by opportunists.

Or... you just drive so slow the gap is constantly growing. You can focus on fuel economy instead.

Re: Hard-braking events as indicators of road segment crash risk

#536

Post by chaz6 »

a_e_k wrote: post #235
maerF0x0 wrote: post #219

Earlier quoted context omitted.

It's frustrating because someone is taking your safety buffer as their opportunity to travel faster. And it results in you having to travel slower and slower to maintain the gap that is constantly consumed, tragedy of the commons style, by opportunists.

Not to mention if that if somebody needs to come over, the proper thing to do is signal first . Then I'm happy to politely ease off a bit and open more space for them to come over safely. It's the people who aggressively slide right over just a few feet in front of me (cutting off nearly all of my safety buffer) without so much as a signal that really drive me nuts.

In the UK we are taught that you should not signal until you are ready to manoeuvre. If you follow the rules exactly this can put you in the unfortunate position of being penned in behind shower traffic.

Re: Hard-braking events as indicators of road segment crash risk

#537

Post by rconti »

Klaus23 wrote: post #357
dietr1ch wrote: post #261

Earlier quoted context omitted.

> Is it one of those cars that alters the brake boost depending on circumstances? No, it's just breaking a bit too hard for you while the panel beeps and has scary red lights pop (that you'll have a hard time reading).

If you are referring to the alert stage of the emergency braking system, triggering it should be rare if you drive reasonably well. It is also most likely a situation in which you could benefit from a little more braking force. If you decide to swerve, the additional weight at the front will help you to initiate the turn, and good systems will then reduce the braking force at the right moment to give you the most tra…

Yeah, most AEB systems I've used work quite well. I've had a couple false alarms (just at the warning stage) where I can at least understand why they happened from a system perspective, even if there was no risk.

I did find "normal" mode on the Model 3 was way too sensitive, but I set it to "late" and it's been fine ever since.

Re: Hard-braking events as indicators of road segment crash risk

#538

Post by thewebguyd »

Sohcahtoa82 wrote: post #366
crest wrote: post #291

Earlier quoted context omitted.

It's wild to me that it's allowed and accepted to overtake on the right on US highways.

The alternative is that you're stuck going 10+ mph under the limit because of a left lane hog. Banning passing on the right only works if keep-right-except-to-pass laws exist and are thoroughly enforced . Most states in the USA don't have keep-right laws, and those that do, it's never enforced, so many people don't even know it's actually the law. EDIT: US-26 westbound immediately outside downtown Portland is notorio…

AFAIK all US states have some form of "keep right" or "slow poke" laws in various forms that distill down to keep right, except to pass.

So the laws do exist, they just are never enforced. Even when said left lane campers cruise by state patrol, I never see them stopped. Hell, I rarely see them stop people going 15+ over the limit either so not actually sure what they're doing.

Re: Hard-braking events as indicators of road segment crash risk

#539

Post by thewebguyd »

maerF0x0 wrote: post #263
Sohcahtoa82 wrote: post #252

Earlier quoted context omitted.

It's wild to me how often the left lane is not the fastest lane. I've had times where the right lane ends up being the fastest. On I-5 near Woodburn, OR, it's 3 lanes. So many drivers, including truckers, will often stay out of the right lane entirely to avoid being caught up in traffic coming on/off. Meanwhile, the left lane is going 5 mph under the limit because there's a left-lane camper somewhere miles ahead. So…

It's not the fastest often because it's oversubscribed and people do not understand that the car has a 3rd, mostly underuntilized, state of neither pedal depressed (ie "coasting") ... so they create cascading braking pileups ...

To be fair, some (automatic) vehicles have such tall gearing that coasting will not slow you down if on a flat, let alone downhill. I've driven a few, and I can't stand them. You have no choice but to tap brakes.

I much prefer cars with short gearing for better engine braking. I continue to choose to drive a manual party for better engine braking.

Re: Hard-braking events as indicators of road segment crash risk

#540

Post by rootusrootus »

luxpir wrote: post #398
rootusrootus wrote: post #284

Earlier quoted context omitted.

> In Britain at least we call it "braking distance" and you're supposed to leave 2 seconds at least between you and the person in front. Count it off a lamp post/sign etc. Indeed, that is the usual definition in the US for following distance. Along with a typical example of how to determine it for yourself. We usually use the term braking distance to describe the distance that would be required to stop the car based…

Thanks for the reply. So then how is following distance determined? It would have to be further than braking distance to be at least as safe?

I do not know how they came up with the 2-4 second following distance recommendation. As you point out, this is in line with what the UK recommends as well. Probably it is a compromise between safety and practicality.

> It would have to be further than braking distance to be at least as safe?

Other way around. Following distance can be less, because the guy you are following cannot stop instantly unless he hits an immovable object or gets into a head-on crash. If he panic stops, then as long as your car performs similarly in braking you just need to have enough distance to allow for your own reaction time.

AFAIK braking distance for most cars is around 5 seconds at highway speed. Few people routinely set their following distance that long.

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