[Yieldway17]

Originally Posted by Thad E Ginathom

They play a part, but we can all see the roads we are driving on, we know how things are, and it is our responsibility to drive accordingly.

Not denying any of your points. Getting from point A to B safely for ourselves and others on the road is the priority #1.

But everyone else on the road need to be thinking on the same page too. We can be super aware, slow down for every small median gaps or even drainage gaps (where two wheelers pop out from), keep our eyes peeled off for humans and cattle jumping out of bushes and still can end up in the same situation the Duster went through.

There are no guarantees doing any of this will prevent us from being in the same situation and someone else watching a CCTV video of us and nitpick about something we did and wrote a verdict that both share the blame.

The biker lost his life and it’s tragic, but responsibility of saving each of our lives need to be on ourselves first rather than putting it in someone else’s defensive driving.

[venkyhere]

Originally Posted by Thad E Ginathom

I wonder... How can a detached wheel move faster than it's parent vehicle? Does that really happen, or does it just look like it because of the slowing of the lost-wheel vehicle?

Have people seen such an event when the parent vehicle has enough wheels to continue at the same speed?

Originally Posted by Arun yadav

Newtons law of motion should not allow that to happen. Could seem to happen / really happen due to the parent vehicle slowing just after separation and the free wheelie gaining momentum on a slope and / or hitting other stuff

Originally Posted by MT_Hyderabad

Not exactly.. Newton second law explains it explicitly.

The wheel attached to car was carrying a load. The wheel detached from car was not carrying any load. Hence, detached wheels are faster than the Parent vehicle.
However, if it is just the wheel cover, it will be slower or max, at the same speed of the car.. As it did not carry any load in the first place.

A refresher of the Newtons second law of motion: F/M = A. Lesser the mass, more the acceleration for the given force.

This is the precise reason why detached wheels jump out of the vehicle and start bouncing, as the sudden disappearance of load makes the Tyre Free and Crazy

The reason is -> rotational inertia or rotational energy which was erstwhile getting applied on a 'flexing' wheel+tyre with a large contact patch is now getting applied on an unflexing wheel+tyre with a much smaller contact patch.
The 'load' tries to squish the tyre to the road and resists the rotation by :
a) surface contact friction that is linearly proportional to the weight squishing it down
b) rolling resistance offered by the flexing rubber - more the contact patch, bigger the flexing, because the sidewalls of the tyre have to suffer a higher change in shape as they near the contact patch location. This change in shape and bouncing back to shape consumes energy, and shows up as 'heat' on the tyre due to the polymer long chain molecules rubbing with each other. This is why the air inside the tyre heats up as well, through contact with the inner walls of rubber (which in turns shows up as higher tyre pressure in your TPMS readouts).
So the 'tractive effort' of the drivetrain is spent overcoming (a) and (b) => the higher the weight/mass squishing the tyre, the more tractive effort is required - that's why more fuel gets burned pulling a fully occupied vehicle, in comparison to a vehicle with only driver.

When the 'load' disappears suddenly, the rotational inertia possessed by the wheel+tyre immediately finds lesser resistance to continue rotating, and hence actually accelerates faster than the vehicle from which it just came free from.

[SJM1214]

Ahmedabad river front.

[Arun yadav]

Originally Posted by venkyhere

The reason is -> rotational inertia or rotational energy which was erstwhile getting applied on a 'flexing' wheel+tyre with a large contact patch is now getting applied on an unflexing wheel+tyre with a much smaller contact patch.
The 'load' tries to squish the tyre to the road and resists the rotation by :
a) surface contact friction that is linearly proportional to the weight squishing it down
b) rolling resistance offered by the flexing rubber - more the contact patch, bigger the flexing, because the sidewalls of the tyre have to suffer a higher change in shape as they near the contact patch location. This change in shape and bouncing back to shape consumes energy, and shows up as 'heat' on the tyre due to the polymer long chain molecules rubbing with each other. This is why the air inside the tyre heats up as well, through contact with the inner walls of rubber (which in turns shows up as higher tyre pressure in your TPMS readouts).
So the 'tractive effort' of the drivetrain is spent overcoming (a) and (b) => the higher the weight/mass squishing the tyre, the more tractive effort is required - that's why more fuel gets burned pulling a fully occupied vehicle, in comparison to a vehicle with only driver.

When the 'load' disappears suddenly, the rotational inertia possessed by the wheel+tyre immediately finds lesser resistance to continue rotating, and hence actually accelerates faster than the vehicle from which it just came free from.

Vow, quite some heavy stuff and definitely makes sense as well.
some folks also claim this is a topic of debate among post-doc physicist as well

Some additional views / counterviews:-
https://ask.metafilter.com/49668/Why...r-than-the-car

https://physics.stackexchange.com/qu...-vehicle-speed

[adisan]

Originally Posted by GutsyGibbon

What is with these TV hosts, looping the video and explaining the same thing over and over again.

And on some occasions, their narrative takes the "bigger vehicle at fault" line whereas the video might suggest otherwise to viewers.

Originally Posted by Yieldway17

We can be super aware, slow down for every small median gaps or even drainage gaps (where two wheelers pop out from), keep our eyes peeled off for humans and cattle jumping out of bushes and still can end up in the same situation the Duster went through.

Agree that incidents can still happen even when a person takes utmost care.

But there is an additional factor - a person knowing that s/he has taken all possible precautions to avoid trouble (at least for themselves), no matter who might be right or wrong. Especially given that a few others on the road might not be taking adequate care.

[Gansan]

The best way to drive on our roads is to expect the unexpected. Expect people or animals to jump out of the median. Expect people to drive on the wrong side of the road, and come on you unexpectedly. Whenever you see people or vehicles around, don't be shy to use the horn and make your presence felt. Honking may be considered as bad manners and looked down upon in the west, but not here. For us the horn is a primary safety device.

Most importantly keep the speed down when the road passes through populated areas, even if there are FOBs present. People will still dart across the road. Even when on highways, keep to the speed limit or slightly above it. Very high speeds are not advisable on our highways. Don't drive on the right most lane, the centre lane is best. Especially on curves, where our straight line visibility may be curtailed by the tall bushes on the median.

In short, expect that everyone other than you on the road is a fool and you will have to compensate for their errors. That is the best defensive strategy for our roads. This may not save us from accident hundred percent, but the probability of a mishap will be very very small.

[Bhargav7]

Originally Posted by Yieldway17

I honestly don’t blame the Duster at all in this situation. If we have to slow down (more than the speed limit) for every uncontrolled intersections and gaps in our ‘highways’, we will have to crawl every half KM.

Duster has the right of way, it doesn’t have any Give Way/Stop signs or any other traffic control device for them to give way to the biker, the biker crossed multiple lanes at the same time etc.. If the Duster was going above the speed limit, at best they will get a speeding ticket legally. Defensive driving is a different argument and let’s be honest - no one is driving 100% defensive all the time on the road, even the best among us in this forum.

Generally, most highways have markings before an intersection or where there is a gap in the median. And the expectation is that vehicles slow down even if they have to crawl. Fellow BHPian MT_Hyderabad recently posted a very good video on this topic in this thread. I guess this is required by law in India - not sure, though. Probably other BHPians can throw some light.

On your second point of getting away with a speeding ticket in case of an accident caused by overspeeding, something did not sound right about it. I did a quick google search and found this -

If the driver of any vehicle causes an accident due to negligent and rash driving, resulting in any physical injuries to a person, then they are considered guilty under Section 279 of the Indian Penal Code. The individual will also be guilty under Section 337 of IPC (causing harm by an act that endangers personal safety or the life of other people), and Section 338 of IPC (causing severe injuries by an act that endangers personal safety or the life of other people).

In case the driver of the vehicle is under the influence of alcohol or other intoxicants and causes an accident that results in the death of a person, they will be considered guilty under Section 304A of the IPC.

This clearly states that Sec 279 IPC only deals with negligent and rash driving/riding on public roads that can put the lives of other people in danger. However, if the driver causes death or any bodily injuries to other people, then the person is also charged under Section 337, Section 338, and Section 304A of the Indian Penal Code.

https://www.bajajfinservmarkets.in/i...pc-mv-act.html

[venkyhere]

Originally Posted by Arun yadav

Some additional views / counterviews:-
https://ask.metafilter.com/49668/Why...r-than-the-car

https://physics.stackexchange.com/qu...-vehicle-speed

Is anyone talking about the 'massively flexing' rubber suddenly getting the liberty to not flex much at all ? which means the energy distribution which was erstwhile 95% kinetic, 5% flexing heat (some heuristic number) is suddenly getting to become 99% kinetic, 1% flexing heat
(the numbers are just pulled out of a hat, just for a qualitative sense)

[sunikkat]

Originally Posted by SJM1214

Ahmedabad river front.

What is that orange colour wheel there? From the pics there are 2 vehicles that met with accident, and that wheel doesnt look like belong to any of them.

Or is that a Porsche in the first pic and then 2 other cars?

[Chetan_Rao]

Originally Posted by sunikkat

What is that orange colour wheel there? From the pics there are 2 vehicles that met with accident, and that wheel doesnt look like belong to any of them.

Or is that a Porsche in the first pic and then 2 other cars?

Spare wheel from the Porsche (example). The stuff strewn about there seems like contents of its boot.

[sparky@home]

A bike accident for which I was a witness, nothing happened due to sheer luck, and the traffic was light at that time, when it's normally heavy.

https://youtu.be/gIpxIG6d7iA

[poised2drive]

https://www.youtube.com/watch?v=ksflG5jkZ-M

This is tragically sad !

In an attempt to save an injured bird, 2 men lose their lives as a taxi hits them on Bandra-Worli Sealink.

Though it is not the brightest of the ideas to stop on such busy roads, there was enough room for the car to pass through and had no visibility problems.

I wonder if the taxi driver was under highway hypnosis- just proceeds straight and hits the pedestrians without any attempts of braking and swerving .

[deathwalkr]

We have a huge sense of false security while on the road. And we seem to put the onus on safety on others!

At the very least one of them could have faced the oncoming traffic as a guide to the traffic seeing as they decided to stop the car and get down on what looks to be a very busy high speed stretch.

The taxi driver did seem to have enough time to take evasive action but who knows what went through his head when he saw two gents standing on the highway.

Like someone said, our roads we need to watch out for the unexpected all the time.

Good intentions but ultimately paid the price.

[Chetan_Rao]

Tragic, and completely unnecessary!

That video isn't the best quality so it isn't obvious whether their hazard lights are on or they've put down their hazard warning triangle.

What's obvious is their absolute obliviousness to high-speed traffic whizzing past them. The gentleman in the darker colored shirt nearly gets collected by the swerving white car earlier in the clip, and the one in the light colored shirt nearly walks backwards into the adjacent lane more than once.

It's dangerous enough being stationary mid-road in congested urbanity (like the tripling bike chaps in an example recently), but doing it on an active carriageway where even cars at legal speeds are doing ~80 kmph?

[StopUnderrides]

Originally Posted by deathwalkr

Good intentions but ultimately paid the price.

True. Good intentions matter only if you are alive. The outcome matters.

Originally Posted by venkyhere

When the 'load' disappears suddenly, the rotational inertia possessed by the wheel+tyre immediately finds lesser resistance to continue rotating, and hence actually accelerates faster than the vehicle from which it just came free from.

Not denying this as a reason. Another reason is that the tyres are flexible and some energy is stored as potential energy due to torsion of the tyre. This gets released because under no load there’s little torsion.

Think of how sprinters get an initial “jump” when the stored potential energy in the muscle translates into kinetic energy.