Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Hard-braking events as indicators of road segment crash risk

research.google

Post reply on HN
Print view View original

391–400 of 577 posts

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

#391

Post by throwup238 »

adw wrote: post #390
apparent wrote: post #382

Earlier quoted context omitted.

It is more dangerous to be slow and have people constantly merging in front of you, rather than be slightly faster and not have all the merging. Accidents happen when vehicles are going different speeds, all things equal.

American road laws are insane here. The law should be simple; you must be in the outside lane at all times unless you are overtaking, and once you're done overtaking, you should merge back into the outside lane. https://www.highwaycodeuk.co.uk/overtaking.html

As far as I know that’s the law in every state I’ve driven in, but enforcement is pretty much nonexistent. Some states like Texas or Louisiana might have signs reminding people to stay out of the inner lanes except for passing but I’ve never heard of anyone getting a ticket over it. What’s enforcement like in the UK?

For example, the specific law in California: https://leginfo.legislature.ca.gov/faces/codes_displaySectio...

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

#392

Post by consp »

CGMthrowaway wrote: post #365
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 "…

Of course braking/change in velocity creates waves. But this effect is overemphasized in my opinion. Locally analyzed, traffic can be simplified incredibly by observing that a lane's maximum throughput is simply given by following spacing, measured in time. If drivers are using a 2 second following distance, commonly taught in driving school, then max throughput is simply 1 car / 2 sec If you double following distanc…

If you take this measurement as the goal it would be best at near standstill speed (around 4m/s). If you want to maximize the traveled distance of the group it is around 60kph, which is the metric most people actually care about when discussing throughput.

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

#393

Post by tiagod »

JimBlackwood wrote: post #106
advisedwang wrote: post #14

Earlier quoted context omitted.

Insurance is thinking about hard braking as an indicator of a driver with riskier behaviour. Google is showing that it can also be an indicator of risky road designs. These actually kind of point in opposite directions in terms of the causes of hard braking. The certainly can be used in different ways.

They point in opposite directions because they’re not measuring the same things. Google is measuring where on the road most hard braking events happen. Insurers measure who is having the most hard braking events.

Problem with insurance companies measuring risk this way is that local government externalises costs of bad road design to the people who are unfortunate to have to drive there.

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

#394

Post by littlestymaar »

chad_oliver wrote: post #143
mschuster91 wrote: post #74

Earlier quoted context omitted.

Yeah well fuck insurers. We are supposed to get spied upon by our cars with their blackboxes, by our insurers, by Google, by national security services of various countries... and what do we get in return? Dinged for other people's bad behavior which we cannot reasonably control. Either you follow the car in front of you very closely and get hard braking events, or other people switch lanes in front of you and in the…

Credit scores are universally hated but they make it possible to offer lower interest rates to more people. Without credit scores, fewer people would have access to credit. Similarly, people often don't like it when insurers track and score their driving. However, this allows insurers to offer lower insurance fees to more people by _not_ offering lower insurance fees (or instead charging higher fees) to people that a…

> Credit scores are universally hated but they make it possible to offer lower interest rates to more people.

That's probably true in theory, but not in practice, given how high US credit interest rates are compared to European countries for instance.

> Without credit scores, fewer people would have access to credit.

Too many people having access to credit is exactly how we got the worst financial crisis of the century, so it's not really something to brag about… People talk about US public debt a lot, but private debt is even more worrisome.

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

#395

Post by silisili »

Sohcahtoa82 wrote: post #252
c22 wrote: post #240

Earlier quoted context omitted.

It seems like a tragedy, but actually it can be a boon as long as you travel in neither the leftmost nor rightmost lane . The majority of the traffic entering your buffer will be exiting your buffer out the other side as soon as they can, so you can just chug along at a (greatly reduced, but) consistent speed. Meanwhile, the traffic to either side of you is in standstill, paralyzed by your bow wake.

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…

This is what most frustrates me about driving in Florida. The right lane is nearly always the fast lane, yet is the lane with most 'events.'

When asked, they'll say they feel safer in the left lane because they don't feel safe having to deal with people turning out and merging. So you get instead people driving fast in the lane meant for pulling out and merging.

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

#397

Post by littlestymaar »

bramblerose wrote: post #378
Gigachad wrote: post #358

Earlier quoted context omitted.

Because for air travel we pre filter out the morons who are drunk, untrained, scrolling facebook, etc. Any incident left is overwhelmingly more likely a systems issue. For a road incident, the most likely cause was just one driver was violating one or more rules. The only system failure was not canceling their license beforehand.

While that is true, "Drivers consistently ignoring rules" is also a systems issue, which can be mitigated through e.g. better road design (narrower roads reduce speeding, for example).

Or “design cities to be less car centric so we can keep the antisocial drivers out of a car”. It's definitely a system issue.

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

#398

Post by luxpir »

rootusrootus wrote: post #284
luxpir wrote: post #210

Wait, what do they teach in North America? Never heard the term "following distance" before now. Sounds misleading. 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. In certain at-risk areas they use chevrons on the road and signs telling you to keep at least 2 chevrons between you and the car in fr…

> 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?

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

#399

Post by Mawr »

apparent wrote: post #382
ehnto wrote: post #367

Earlier quoted context omitted.

I understand perfectly, 20 years driving, I think people just don't like that the safe answer is to be slow. You will not fix others behaviour, so your options are be slow and generous, get out of the chaotic lanes (unless that's all of them), or join them and be aggressive, claim space, be stressed and annoyed your whole trip. There is no solution to traffic here sorry, this is more about managing your own frustrati…

It is more dangerous to be slow and have people constantly merging in front of you, rather than be slightly faster and not have all the merging. Accidents happen when vehicles are going different speeds, all things equal.

This is dangerous nonsense. It's basically just a justification people find in order to feel good about their unsafe driving.

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

#400

Post by kortilla »

crazygringo wrote: post #331
ehnto wrote: post #326

Earlier quoted context omitted.

Slow down a bit to create another buffer. You can even do this before they have merged, as part of the bit where you allow them to safely merge. I think if you reflect a bit you'll find you are being the same kind of person as them, if you are getting angry that you have to slow down and give up space for someone else. I understand some people can be aggressive though, that can be frustrating regardless of the outcom…

I don't think you're understanding. The point is that 20 people in a row will take advantage of your buffer to slow you down again and again and again, which makes you get to your destination later... because they're being selfish to get somewhere faster, and you're not so you get to where you're going slower . We're not talking about where they're changing lanes to take the next exit. We're talking about where your…

20 people in a row is like 200 meters. Absolutely negligible to your travel time.
Post reply on HN