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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

#491

Post by ses1984 »

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.

I think there's nothing worse than drivers who feel entitled to go fast at the expense of everyone else's safety.

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

#492

Post by CGMthrowaway »

boisterousness wrote: post #470
CGMthrowaway wrote: post #359

Earlier quoted context omitted.

This is a long thread of people talking past each other. The bottom line is simply this: if you want to drive with a larger-than-average following distance (call it whatever you want, a safety buffer, a "proper" following distance, the point is it is a distance less than the average following distance of the other drivers on the road) then you have to accept that you will not be able to drive at the same speed as the…

Not so. Keeping a constant distance from the car ahead means both cars are moving at the same speed. When a jerk cuts in, after a moment all 3 cars will be moving at the same speed.

We are saying the same thing. When a jerk cuts in, drivers readjust their speed to maintain desired following distance. Net effect, slower speed for all but the lead car

If you personally start with that slower speed to begin with (AKA much longer following distance), you don't have to worry about adjusting down

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

#493

Post by Noumenon72 »

crest wrote: post #292
maerF0x0 wrote: post #263

Earlier quoted context omitted.

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 ...

If everyone that had it turned adaptive cruise control sigh .

The adaptive cruise control in my Subaru rarely coasts. It isn't smart enough to see a gap slowly narrowing and start coasting, and it isn't confident enough to temporarily allow the gap to be smaller than the setpoint while it coasts to recover the gap. So it brakes and wastes energy, and I don't use it.

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

#494

Post by gwbas1c »

maerF0x0 wrote: post #268
gwbas1c wrote: post #145

Earlier quoted context omitted.

I'm one of the faster drivers and I maintain a safe distance. (I usually have the most distance in rush hour.) It's very easy with adaptive cruise control or the other self-driving technologies that are on the market. The only people who cut too close to me are driving recklessly. That being said: If you're in the mode where people are constantly changing lanes in front of you, think a bit about how you're driving: O…

In my place, there's a significant group of drivers who will ride your tail too close hoping you'll move over so they can get 1 car ahead. And if they see more than 0.9 car length in front of you they will do what they can (weaving other lanes) to try and get into that space, 1 car ahead of you. As far as I can tell it's pure selfishness and competitiveness. Their desire isn't to cooperate and arrive it's to take fro…

That's (the tailgaters) reckless driving and very illegal. It's a symptom of poor traffic enforcement.

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

#495

Post by dahcryn »

Sohcahtoa82 wrote: post #371
crest wrote: post #292

Earlier quoted context omitted.

If everyone that had it turned adaptive cruise control sigh .

So many people don't even use regular cruise control. They'll have nobody in front of them for miles and their speed yo-yos between 60 and 65 mph. And if you pass them because your cruise is set at 66 mph, they'll speed up to match, but then eventually decide to pass you, get in front, and slow back down to 60. The only way to end the stupid cycle is to go 70-75 mph until there's at least 1/4 mile between the two of…

and there is a huge overlap between those people, and those who slow down to 60 to save on fuel.

If they'd just drive 70 on cruise control, they'd be faster, less traffic jams and less fuel use...

I really would like to see some mandatory use of cruise control on some stretches of highway, even if just as an experiment

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

#496

Post by gwbas1c »

skue wrote: post #259
thewebguyd wrote: post #179

Earlier quoted context omitted.

> and you're expected to keep up with the flow of traffic. This is very state dependent, if we are talking about legality. In WA state, for example, there is no "flow of traffic" law or similar. The limit is the limit, and any excess of the speed limit is illegal regardless of what all other drivers are doing. So even if the right/slow lane is going 100MPH through the 70MPH zone, you are legally expected to still go…

You’re confused. If you know of ANY US state that has a flow of traffic law that allows cars to exceed the speed limit so long as they are keeping up with other traffic, I’d love to see a link to their traffic codes. Speeding doesn’t suddenly become legal because two or more drivers do it together. This has nothing to do with the expectation that slower traffic stay in the rightmost lanes, which is what GP is address…

> Speeding doesn’t suddenly become legal because two or more drivers do it together.

That's not true. Examples:

I once pulled out my local newspaper where local judges were petitioning to have speed limits raised because they were throwing out speeding tickets due to excessive fines. This was in Massachusetts, in the late 1990s or early 2000s, about a road in Shrewsbury near lake Quinsigamond. The context was that the speed limit was 25, traffic flowed at 40-45, and they would throw out tickets for people doing 50.

I was once pulled over in a Massachusetts tollbooth even though I was the slowest driver on the road. (2004, I90 westbound at the intersection of 128, when EZ Pass still had to go through actual tollbooths.) If I was given an actual ticket, I would have point-blank told the judge that I was going half the speed of everyone else and feared getting rear-ended; then the case would have been dismissed. (The cop also knew this, because he recognized me from traffic court and knew that I'd make him look like a fool for pulling over the slowest driver.)

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

#497

Post by whynotmaybe »

spacecadet wrote: post #474

Defensive driving. Two hands, eyes on the "road", not caring about fools and maintaining safe distances. You have all the time in the world... I Recommend taking your car to a HPDE event, sometimes insurance will discount you for this. In this case, hard braking, is you just not knowing anything about your car or the cars around you... I barely use my brakes, but I also drive manual... Id say learn engine braking but…

https://donmcminn.com/2020/02/we-judge-ourselves-by-our-inte...

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

#498

Post by closewith »

albumen wrote: post #475
closewith wrote: post #446

Earlier quoted context omitted.

That used to be the case in Ireland too, but confusion due to cultural contamination means pretty much everyone moved to numbering lanes (from the "outside"/"slow"/leftmost lane).

I've been driving in Ireland for 30 years and I've never heard anyone number lanes. For me it's left/slow; middle; or right/fast lane.

When I did my B license test probably about 30 years ago, the Rules of the Road all referenced inside/outside lanes. When I did my CE license last year, it had been updated to only use lanes 1, 2, 3 etc.

Obviously fast and slow are just colloquial terms.

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

#499

Post by Natsu »

rogerrogerr wrote: post #482
thechao wrote: post #443

Earlier quoted context omitted.

I object to the "late" argument made by etho's parent. The difference in time to destination will inevitably be dominated by lights, in city travel, not by modest speed differences (say 45 vs 55) on a highway. Being safe & out of the way is the trick! It would be nice if we got rid of left & u turns and build our roads for that!

45 vs. 55 is not modest; that's 5 minutes over only 20 miles. Up around 60 vs. 70 is where it becomes "modest" IMO.

So, 3 stoplights worth of time?

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

#500

Post by Spooky23 »

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…

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 arbitrary self imposed practice that is leading to 20 drivers cutting in front of you, are the one creating an unsafe situation.

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