On 05/01/2024 11:28, Spike wrote:
> Clive Page <usenet@page2.eu> wrote:
>> On 05/01/2024 09:56, Jethro_uk wrote:
>>> I recently read a suggestion that some potholes in the UK may be due to
>>> the action of EV acceleration.
>>>
>>> If true it's a good reason to tax them more.
>>
>> It seems to be well established that damage to roads is roughly
>> proportional to the fourth power of the weight of the vehicle. I can't
>> find a good estimate of the average weight of an electric vehicle
>> compared to one with a petrol/diesel engine, but I have seen figures that
>> they are around 30% heavier because of the battery. This would make the
>> road damage 2.8 times higher.
>>
>> Of course governments everywhere have chosen to ignore this when taxing
>> 40 ton trucks, otherwise they would pay about 2.5 million times as much
>> as a one-ton car for the road damage element of their tax.
>
> Let look at a few real world numbers.
>
> The bicycle and rider:
>
> Weight…100kg
>
> Number of axles…2
>
> Size of contact one patch…2800 mm^2
>
> Load exerted on the road surface by one wheel =
>
> (100/2)/(2800x(10^-6) kg/sq.m
>
> = 1.8x(10^4) kg/sq.m
>
> The car:
>
> Weight…2000kg
>
> Number of axles….4
>
> Size of one contact patch…20500mm^2
>
> Load exerted on the road surface by one wheel =
>
> (2000/4)/(20500x(10^-6) =
>
> = 2.4x(10^4) kg/sq.m
>
> So from this analysis it can be seen that actual loads exerted on the road
> surface through the combination of the contact patch of the tyre and the
> loads acting through it are very similar for the case of the bicycle and
> the larger modern car.
>
> Nowhere in these calculations was it necessary to invoke some ‘fourth
> power’ ‘rule’. Contact patch sizes were obtained from cycling and motoring
> web sites.
>
> I suspect that the EV/pothole issue stems from the EV being able to exert
> more torque at the road wheels at zero speed, than an ICE vehicle.
>
Yes, but when the bicycle gets to the far side of the pothole (assuming that the rider hasn't been thrown off) then the road surface only has to lift a load of about 100 kg, whereas when a 2 ton car gets to the other side the road surface has to lift most of 2 tons. It may be that for a continuous good-quality smooth surface the damage difference isn't great, but when you encounter a very rough potholed road the heavier vehicle obviously does a lot more damage.

--
Clive Page

In message <un9r7a$g4q$37@dont-email.me>, Jethro_uk
<jethro_uk@hotmailbin.com> writes
>On Fri, 05 Jan 2024 20:21:28 +0000, NY wrote:
>
>> On 05/01/2024 18:34, Rod Speed wrote:
>>> [quoted text muted]
>>
>> I've always wondered, can the driver configure a maximum acceleration,
>> especially when setting off from rest, which is lower than the maximum
>> that the vehicle can achieve, to avoid accidentally excessive forces? In
>> an ICE car, there is a physical limit which varies with engine power but
>> in most cases is less than what an EV can achieve if not subject to a
>> drover's preferred limit.
>
>Electric *buses* can take off like a jet ....

I remember the trolleybuses of the 1950s and early 60s. They could
certainly have a pretty rapid take-off.
--
Ian
Aims and ambitions are neither attainments nor achievements

On 05/01/2024 21:10, SteveW wrote:
> On 05/01/2024 14:44, Colin Bignell wrote:
>> On 05/01/2024 09:56, Jethro_uk wrote:
>>> I recently read a suggestion that some potholes in the UK may be due to
>>> the action of EV acceleration.
>>>
>>> If true it's a good reason to tax them more.
>>
>> I've not found any reports that support that, but have seen a claim by
>> the suppliers of asphalt that unclassified roads could be in danger
>> from the weight. Classified roads are already built to withstand the
>> weight of HGVs, but unclassified roads, which account for about 60% of
>> the network, are not built to the same standards and some could be at
>> risk from the weight.
>
> Or MG4 is less than 15% heavier than our Zafira, that should have little
> effect on any properly built and maintained road.

Unclassified roads, such as residential streets, would have been built
to suit the traffic of the day and since then have usually had little
more maintenance than the occasional replacement of the wearing surface.
My road was built in 1931. How do your cars compare for weight with cars
from the 1930s?

> Yes, it's acceleration is better, but not exessive ... and how often do
> you suddenly floor a car, from standstill, in normal driving?
>

--
Colin Bignell

NY <me@privacy.net> wrote
> Rod Speed wrote
>> Jethro_uk <jethro_uk@hotmailbin.com> wrote
>>> Clive Page wrote
>>>> Jethro_uk wrote

>>>> It seems to be well established that damage to roads is roughly
>>>> proportional to the fourth power of the weight of the vehicle.

>>> That's one factor. The force of acceleration is another. It creates a
>>> shear force surely ?

>> The problem with that line is that while an EV CAN accelerate
>> faster than an ICE, the reality is that EV drivers don't actually
>> do that in reality so it can't actually produce more potholes.

> I've always wondered, can the driver configure a maximum acceleration,
> especially when setting off from rest, which is lower than the maximum
> that the vehicle can achieve, to avoid accidentally excessive forces?

That's what the accelerator does, no a start by start basis.

> In an ICE car, there is a physical limit which varies with engine power

And there is with any EV car too, what the wheel motors can do.

> but in most cases is less than what an EV can achieve if not subject to
> a drover's preferred limit.

But is limited to what the wheel motors can do.

> Or do EVs have an acceleration profile which starts off low and
> gradually increases, despite constant accelerator position?

No, but they do all still have accelerators. And even self driving
cars and cruise controls which still work right down to stop
start driving like some Honda's do still do smooth starts, they
dont drive like a stupid kid on steroids at the stop lights.

> I ask because we have an electric wheelbarrow and this take thatconcept
> to excess. If you happen to release the twist-grip throttleas you are
> walking along behind it, you risk impaling yourself onthe handlebars
> because a) the barrow stops *very* quickly, andb) it takes a second or
> so for it to even *start* to pick up speedagain; both of these mean
> that you have to actually stop ratherthan just adjusting your walking
> speed a bit.

> I suppose it is easier with an EV than an ICE car to building all sorts
> of things like S-shaped acceleration profiles and artificially limited
> maximum acceleration.

Yeah, much easier to control the wheel motors. And you need to
too, particularly so you dont get wheel spin in wet weather.

On Sat, 06 Jan 2024 09:43:18 +1100, cantankerous trolling geezer Rodent
Speed, the auto-contradicting senile sociopath, blabbered, again:

<FLUSH the abnormal trolling senile cretin's latest trollshit unread>

On 05/01/2024 18:21, Paul wrote:
> Who knows, when vehicles are eventually rationed, they
> will no longer be SUV-sized.

Many years ago I lived on a 4 mile long cul-de-sac where the only
traffic was the half dozen people who lived on it, tractors, combine
harvesters and 30 tonne sugar beet and potato haulers.

There was a slight dip in the otherwise flat road at one point. Over the
ten years that I lived there it got deeper and deeper and moved outbound
from the farms, in the direction the laden sugar beet trucks were
travelling.

I think after I left they must have done something about it.
--
"Fanaticism consists in redoubling your effort when you have
forgotten your aim."

George Santayana

On 05/01/2024 20:21, NY wrote:

>
> I suppose it is easier with an EV than an ICE car to building all sorts
> of things like S-shaped acceleration profiles and artificially limited
> maximum acceleration.

Many cars have fly by wire throttles. Mine certainly does and its a
pain sometimes as it refuses to go until its changed gear and got some
momentum in the turbo.

--
Gun Control: The law that ensures that only criminals have guns.

On 05/01/2024 22:27, Colin Bignell wrote:
> On 05/01/2024 21:10, SteveW wrote:
>> On 05/01/2024 14:44, Colin Bignell wrote:
>>> On 05/01/2024 09:56, Jethro_uk wrote:
>>>> I recently read a suggestion that some potholes in the UK may be due to
>>>> the action of EV acceleration.
>>>>
>>>> If true it's a good reason to tax them more.
>>>
>>> I've not found any reports that support that, but have seen a claim
>>> by the suppliers of asphalt that unclassified roads could be in
>>> danger from the weight. Classified roads are already built to
>>> withstand the weight of HGVs, but unclassified roads, which account
>>> for about 60% of the network, are not built to the same standards and
>>> some could be at risk from the weight.
>>
>> Or MG4 is less than 15% heavier than our Zafira, that should have
>> little effect on any properly built and maintained road.
>
> Unclassified roads, such as residential streets, would have been built
> to suit the traffic of the day and since then have usually had little
> more maintenance than the occasional replacement of the wearing surface.
> My road was built in 1931. How do your cars compare for weight with cars
> from the 1930s?

They probably compare pretty well with narrow wheeled carts and the
remaining solid tyred wagons - especially steam wagons.

On 05/01/2024 21:45, Clive Page wrote:
> On 05/01/2024 11:28, Spike wrote:
>> Clive Page <usenet@page2.eu> wrote:
>>> On 05/01/2024 09:56, Jethro_uk wrote:
>>>> I recently read a suggestion that some potholes in the UK may be due to
>>>> the action of EV acceleration.
>>>>
>>>> If true it's a good reason to tax them more.
>>>
>>> It seems to be well established that damage to roads is roughly
>>> proportional to the fourth power of the weight of the vehicle.  I can't
>>> find a good estimate of the average weight of an electric vehicle
>>> compared to one with a petrol/diesel engine, but I have seen figures
>>> that
>>> they are around 30% heavier because of the battery.  This would make the
>>> road damage 2.8 times higher.
>>>
>>> Of course governments everywhere have chosen to ignore this when taxing
>>> 40 ton trucks, otherwise they would pay about 2.5 million times as much
>>> as a one-ton car for the road damage element of their tax.
>>
>> Let look at a few real world numbers.
>>
>> The bicycle and rider:
>>
>> Weight…100kg
>>
>> Number of axles…2
>>
>> Size of contact one patch…2800 mm^2
>>
>> Load exerted on the road surface by one wheel =
>>
>> (100/2)/(2800x(10^-6) kg/sq.m
>>
>> = 1.8x(10^4) kg/sq.m
>>
>> The car:
>>
>> Weight…2000kg
>>
>> Number of axles….4
>>
>> Size of one contact patch…20500mm^2
>>
>> Load exerted on the road surface by one wheel =
>>
>> (2000/4)/(20500x(10^-6) =
>>
>> = 2.4x(10^4) kg/sq.m
>>
>> So from this analysis it can be seen that actual loads exerted on the
>> road
>> surface through the combination of the contact patch of the tyre and the
>> loads acting through it are very similar for the case of the bicycle and
>> the larger modern car.
>>
>> Nowhere in these calculations was it necessary to invoke some ‘fourth
>> power’ ‘rule’. Contact patch sizes were obtained from cycling and
>> motoring
>> web sites.
>>
>> I suspect that the EV/pothole issue stems from the EV being able to exert
>> more torque at the road wheels at zero speed, than an ICE vehicle.
>>
> Yes, but when the bicycle gets to the far side of the pothole (assuming
> that the rider hasn't been thrown off) then the road surface only has to
> lift a load of about 100 kg, whereas when a 2 ton car gets to the other
> side the road surface has to lift most of 2 tons.  It may be that for a
> continuous good-quality smooth surface the damage difference isn't
> great, but when you encounter a very rough potholed road the heavier
> vehicle obviously does a lot more damage.

It is still 100kg on a narrow tyre, compared to 1600kg, spread over four
wheels and each wheel being a lot wider.

NY <me@privacy.net> wrote:
> Or do EVs have an acceleration profile which starts off low and
> gradually increases, despite constant accelerator position? I ask
> because we have an electric wheelbarrow and this take that concept to
> excess. If you happen to release the twist-grip throttle as you are
> walking along behind it, you risk impaling yourself on the handlebars
> because a) the barrow stops *very* quickly, and b) it takes a second or
> so for it to even *start* to pick up speed again; both of these mean
> that you have to actually stop rather than just adjusting your walking
> speed a bit.

There are typically different profiles like Eco and Sport that set
acceleration, regen, suspension and other parameters, especially if the car
has multiple 'personalities' - eg highway driving, sports car or off road
features.

Theo

On 06/01/2024 01:15, SteveW wrote:
> On 05/01/2024 22:27, Colin Bignell wrote:
>> On 05/01/2024 21:10, SteveW wrote:
>>> On 05/01/2024 14:44, Colin Bignell wrote:
>>>> On 05/01/2024 09:56, Jethro_uk wrote:
>>>>> I recently read a suggestion that some potholes in the UK may be
>>>>> due to
>>>>> the action of EV acceleration.
>>>>>
>>>>> If true it's a good reason to tax them more.
>>>>
>>>> I've not found any reports that support that, but have seen a claim
>>>> by the suppliers of asphalt that unclassified roads could be in
>>>> danger from the weight. Classified roads are already built to
>>>> withstand the weight of HGVs, but unclassified roads, which account
>>>> for about 60% of the network, are not built to the same standards
>>>> and some could be at risk from the weight.
>>>
>>> Or MG4 is less than 15% heavier than our Zafira, that should have
>>> little effect on any properly built and maintained road.
>>
>> Unclassified roads, such as residential streets, would have been built
>> to suit the traffic of the day and since then have usually had little
>> more maintenance than the occasional replacement of the wearing
>> surface. My road was built in 1931. How do your cars compare for
>> weight with cars from the 1930s?
>
> They probably compare pretty well with narrow wheeled carts and the
> remaining solid tyred wagons - especially steam wagons.

Those would be using the same roads as today's HGVs and those roads are
not expected to cause any problems. It is country lanes and residential
roads that they are worried about. Simply looking at my own vehicle
history shows the way that vehicle weights have grown. My first car, a
medium sized saloon, made in 1959, weighed about 16cwt. By the 1970s, I
was driving a Triumph 2.5pi, which was a big car for its day and that
weighed in at 1.2 tonnes. My current vehicle is half a tonne heavier
than that. Your MG4 may only be 15% heavier that your Zafira, but they
are both a lot heavier than the cars these roads were built for and that
15% could be the straw that breaks the camel's back.

--
Colin Bignell

Clive Page <usenet@page2.eu> wrote:
> On 05/01/2024 11:28, Spike wrote:
>> Clive Page <usenet@page2.eu> wrote:
>>> On 05/01/2024 09:56, Jethro_uk wrote:
>>>> I recently read a suggestion that some potholes in the UK may be due to
>>>> the action of EV acceleration.
>>>>
>>>> If true it's a good reason to tax them more.
>>>
>>> It seems to be well established that damage to roads is roughly
>>> proportional to the fourth power of the weight of the vehicle. I can't
>>> find a good estimate of the average weight of an electric vehicle
>>> compared to one with a petrol/diesel engine, but I have seen figures that
>>> they are around 30% heavier because of the battery. This would make the
>>> road damage 2.8 times higher.
>>>
>>> Of course governments everywhere have chosen to ignore this when taxing
>>> 40 ton trucks, otherwise they would pay about 2.5 million times as much
>>> as a one-ton car for the road damage element of their tax.
>>
>> Let look at a few real world numbers.
>>
>> The bicycle and rider:
>>
>> Weight…100kg
>>
>> Number of axles…2
>>
>> Size of contact one patch…2800 mm^2
>>
>> Load exerted on the road surface by one wheel =
>>
>> (100/2)/(2800x(10^-6) kg/sq.m
>>
>> = 1.8x(10^4) kg/sq.m
>>
>> The car:
>>
>> Weight…2000kg
>>
>> Number of axles….4
>>
>> Size of one contact patch…20500mm^2
>>
>> Load exerted on the road surface by one wheel =
>>
>> (2000/4)/(20500x(10^-6) =
>>
>> = 2.4x(10^4) kg/sq.m
>>
>> So from this analysis it can be seen that actual loads exerted on the road
>> surface through the combination of the contact patch of the tyre and the
>> loads acting through it are very similar for the case of the bicycle and
>> the larger modern car.
>>
>> Nowhere in these calculations was it necessary to invoke some ‘fourth
>> power’ ‘rule’. Contact patch sizes were obtained from cycling and motoring
>> web sites.
>>
>> I suspect that the EV/pothole issue stems from the EV being able to exert
>> more torque at the road wheels at zero speed, than an ICE vehicle.

> Yes, but when the bicycle gets to the far side of the pothole (assuming
> that the rider hasn't been thrown off) then the road surface only has to
> lift a load of about 100 kg, whereas when a 2 ton car gets to the other
> side the road surface has to lift most of 2 tons. It may be that for a
> continuous good-quality smooth surface the damage difference isn't great,
> but when you encounter a very rough potholed road the heavier vehicle
> obviously does a lot more damage.

Think of load per unit area, rather than load. And we were speaking of the
mechanism of generating potholes, not of making existing potholes worse.

--
Spike

On 06/01/2024 09:42, Colin Bignell wrote:
> On 06/01/2024 01:15, SteveW wrote:
>> On 05/01/2024 22:27, Colin Bignell wrote:
>>> On 05/01/2024 21:10, SteveW wrote:
>>>> On 05/01/2024 14:44, Colin Bignell wrote:
>>>>> On 05/01/2024 09:56, Jethro_uk wrote:
>>>>>> I recently read a suggestion that some potholes in the UK may be
>>>>>> due to
>>>>>> the action of EV acceleration.
>>>>>>
>>>>>> If true it's a good reason to tax them more.
>>>>>
>>>>> I've not found any reports that support that, but have seen a claim
>>>>> by the suppliers of asphalt that unclassified roads could be in
>>>>> danger from the weight. Classified roads are already built to
>>>>> withstand the weight of HGVs, but unclassified roads, which account
>>>>> for about 60% of the network, are not built to the same standards
>>>>> and some could be at risk from the weight.
>>>>
>>>> Or MG4 is less than 15% heavier than our Zafira, that should have
>>>> little effect on any properly built and maintained road.
>>>
>>> Unclassified roads, such as residential streets, would have been
>>> built to suit the traffic of the day and since then have usually had
>>> little more maintenance than the occasional replacement of the
>>> wearing surface. My road was built in 1931. How do your cars compare
>>> for weight with cars from the 1930s?
>>
>> They probably compare pretty well with narrow wheeled carts and the
>> remaining solid tyred wagons - especially steam wagons.
>
> Those would be using the same roads as today's HGVs and those roads are
> not expected to cause any problems. It is country lanes and residential
> roads that they are worried about. Simply looking at my own vehicle
> history shows the way that vehicle weights have grown. My first car, a
> medium sized saloon, made in 1959, weighed about 16cwt. By the 1970s, I
> was driving a Triumph 2.5pi, which was a big car for its day and that
> weighed in at 1.2 tonnes. My current vehicle is half a tonne heavier
> than that. Your MG4 may only be 15% heavier that your Zafira, but they
> are both a lot heavier than the cars these roads were built for and that
> 15% could be the straw that breaks the camel's back.

But they are also on much wider and larger tyres, with far greater
contactr patches.

On 06/01/2024 11:16, Spike wrote:

> Think of load per unit area, rather than load. And we were speaking of the
> mechanism of generating potholes, not of making existing potholes worse.
>
No.
The whole FUNCTION of a road is in fact to transfer load per unit area
to load *over a much bigger area.*

Your thinking is as erroneous as comparing the force a train wheel
exerts on a rail with the force the sleeper exerts on the ballast or the
ballast on the ground underneath...

Road deformation is pretty much a function of axle loading, since the
two (or four) wheels are close enough to combine forces to literally
bend the road enough to crack it.

Then water gets in, freezes, and you have a pothole. Once the surface
has gone the substrate is porous and freezes again and cracks up some more.

--
“The ultimate result of shielding men from the effects of folly is to
fill the world with fools.”

Herbert Spencer

On 06/01/2024 11:24, SteveW wrote:

> But they are also on much wider and larger tyres, with far greater
> contactr patches.
>
In the context of potholes, this is completely irrelevant

--
For every complex problem there is an answer that is clear, simple, and
wrong.

H.L.Mencken

On 06/01/2024 12:19, The Natural Philosopher wrote:
> On 06/01/2024 11:24, SteveW wrote:
>
>> But they are also on much wider and larger tyres, with far greater
>> contactr patches.
>>
> In the context of potholes, this is completely irrelevant

Are you saying the stress placed on a road doesn't matter when it comes
to forming potholes?

Did you do a course in art perchance? Engineering is certainly not your
forte.

On 06/01/2024 11:24, SteveW wrote:
> On 06/01/2024 09:42, Colin Bignell wrote:
>> On 06/01/2024 01:15, SteveW wrote:
>>> On 05/01/2024 22:27, Colin Bignell wrote:
>>>> On 05/01/2024 21:10, SteveW wrote:
>>>>> On 05/01/2024 14:44, Colin Bignell wrote:
>>>>>> On 05/01/2024 09:56, Jethro_uk wrote:
>>>>>>> I recently read a suggestion that some potholes in the UK may be
>>>>>>> due to
>>>>>>> the action of EV acceleration.
>>>>>>>
>>>>>>> If true it's a good reason to tax them more.
>>>>>>
>>>>>> I've not found any reports that support that, but have seen a
>>>>>> claim by the suppliers of asphalt that unclassified roads could be
>>>>>> in danger from the weight. Classified roads are already built to
>>>>>> withstand the weight of HGVs, but unclassified roads, which
>>>>>> account for about 60% of the network, are not built to the same
>>>>>> standards and some could be at risk from the weight.
>>>>>
>>>>> Or MG4 is less than 15% heavier than our Zafira, that should have
>>>>> little effect on any properly built and maintained road.
>>>>
>>>> Unclassified roads, such as residential streets, would have been
>>>> built to suit the traffic of the day and since then have usually had
>>>> little more maintenance than the occasional replacement of the
>>>> wearing surface. My road was built in 1931. How do your cars compare
>>>> for weight with cars from the 1930s?
>>>
>>> They probably compare pretty well with narrow wheeled carts and the
>>> remaining solid tyred wagons - especially steam wagons.
>>
>> Those would be using the same roads as today's HGVs and those roads
>> are not expected to cause any problems. It is country lanes and
>> residential roads that they are worried about. Simply looking at my
>> own vehicle history shows the way that vehicle weights have grown. My
>> first car, a medium sized saloon, made in 1959, weighed about 16cwt.
>> By the 1970s, I was driving a Triumph 2.5pi, which was a big car for
>> its day and that weighed in at 1.2 tonnes. My current vehicle is half
>> a tonne heavier than that. Your MG4 may only be 15% heavier that your
>> Zafira, but they are both a lot heavier than the cars these roads were
>> built for and that 15% could be the straw that breaks the camel's back.
>
> But they are also on much wider and larger tyres, with far greater
> contactr patches.
>

The concern expressed was about the weight, not the ground pressure.
However, the ground pressure is roughly the pressure in the tyres. My
first car had a tyre pressure of 20psi. The 2.5PI was 24psi and my
current car is 32psi.

--
Colin Bignell

On 06/01/2024 13:13, Colin Bignell wrote:
> On 06/01/2024 11:24, SteveW wrote:
>> On 06/01/2024 09:42, Colin Bignell wrote:
>>> On 06/01/2024 01:15, SteveW wrote:
>>>> On 05/01/2024 22:27, Colin Bignell wrote:
>>>>> On 05/01/2024 21:10, SteveW wrote:
>>>>>> On 05/01/2024 14:44, Colin Bignell wrote:
>>>>>>> On 05/01/2024 09:56, Jethro_uk wrote:
>>>>>>>> I recently read a suggestion that some potholes in the UK may be
>>>>>>>> due to
>>>>>>>> the action of EV acceleration.
>>>>>>>>
>>>>>>>> If true it's a good reason to tax them more.
>>>>>>>
>>>>>>> I've not found any reports that support that, but have seen a
>>>>>>> claim by the suppliers of asphalt that unclassified roads could
>>>>>>> be in danger from the weight. Classified roads are already built
>>>>>>> to withstand the weight of HGVs, but unclassified roads, which
>>>>>>> account for about 60% of the network, are not built to the same
>>>>>>> standards and some could be at risk from the weight.
>>>>>>
>>>>>> Or MG4 is less than 15% heavier than our Zafira, that should have
>>>>>> little effect on any properly built and maintained road.
>>>>>
>>>>> Unclassified roads, such as residential streets, would have been
>>>>> built to suit the traffic of the day and since then have usually
>>>>> had little more maintenance than the occasional replacement of the
>>>>> wearing surface. My road was built in 1931. How do your cars
>>>>> compare for weight with cars from the 1930s?
>>>>
>>>> They probably compare pretty well with narrow wheeled carts and the
>>>> remaining solid tyred wagons - especially steam wagons.
>>>
>>> Those would be using the same roads as today's HGVs and those roads
>>> are not expected to cause any problems. It is country lanes and
>>> residential roads that they are worried about. Simply looking at my
>>> own vehicle history shows the way that vehicle weights have grown. My
>>> first car, a medium sized saloon, made in 1959, weighed about 16cwt.
>>> By the 1970s, I was driving a Triumph 2.5pi, which was a big car for
>>> its day and that weighed in at 1.2 tonnes. My current vehicle is half
>>> a tonne heavier than that. Your MG4 may only be 15% heavier that your
>>> Zafira, but they are both a lot heavier than the cars these roads
>>> were built for and that 15% could be the straw that breaks the
>>> camel's back.
>>
>> But they are also on much wider and larger tyres, with far greater
>> contactr patches.
>>
>
> The concern expressed was about the weight, not the ground pressure.
> However, the ground pressure is roughly the pressure in the tyres. My
> first car had a tyre pressure of 20psi. The 2.5PI was 24psi and my
> current car is 32psi.
>
My first had 30 psi. Currently its 32.

But irrelevant to potholes

--
WOKE is an acronym... Without Originality, Knowledge or Education.

On 06/01/2024 13:37, The Natural Philosopher wrote:
> On 06/01/2024 13:13, Colin Bignell wrote:
>> On 06/01/2024 11:24, SteveW wrote:
>>> On 06/01/2024 09:42, Colin Bignell wrote:
>>>> On 06/01/2024 01:15, SteveW wrote:
>>>>> On 05/01/2024 22:27, Colin Bignell wrote:
>>>>>> On 05/01/2024 21:10, SteveW wrote:
>>>>>>> On 05/01/2024 14:44, Colin Bignell wrote:
>>>>>>>> On 05/01/2024 09:56, Jethro_uk wrote:
>>>>>>>>> I recently read a suggestion that some potholes in the UK may
>>>>>>>>> be due to
>>>>>>>>> the action of EV acceleration.
>>>>>>>>>
>>>>>>>>> If true it's a good reason to tax them more.
>>>>>>>>
>>>>>>>> I've not found any reports that support that, but have seen a
>>>>>>>> claim by the suppliers of asphalt that unclassified roads could
>>>>>>>> be in danger from the weight. Classified roads are already built
>>>>>>>> to withstand the weight of HGVs, but unclassified roads, which
>>>>>>>> account for about 60% of the network, are not built to the same
>>>>>>>> standards and some could be at risk from the weight.
>>>>>>>
>>>>>>> Or MG4 is less than 15% heavier than our Zafira, that should have
>>>>>>> little effect on any properly built and maintained road.
>>>>>>
>>>>>> Unclassified roads, such as residential streets, would have been
>>>>>> built to suit the traffic of the day and since then have usually
>>>>>> had little more maintenance than the occasional replacement of the
>>>>>> wearing surface. My road was built in 1931. How do your cars
>>>>>> compare for weight with cars from the 1930s?
>>>>>
>>>>> They probably compare pretty well with narrow wheeled carts and the
>>>>> remaining solid tyred wagons - especially steam wagons.
>>>>
>>>> Those would be using the same roads as today's HGVs and those roads
>>>> are not expected to cause any problems. It is country lanes and
>>>> residential roads that they are worried about. Simply looking at my
>>>> own vehicle history shows the way that vehicle weights have grown.
>>>> My first car, a medium sized saloon, made in 1959, weighed about
>>>> 16cwt. By the 1970s, I was driving a Triumph 2.5pi, which was a big
>>>> car for its day and that weighed in at 1.2 tonnes. My current
>>>> vehicle is half a tonne heavier than that. Your MG4 may only be 15%
>>>> heavier that your Zafira, but they are both a lot heavier than the
>>>> cars these roads were built for and that 15% could be the straw that
>>>> breaks the camel's back.
>>>
>>> But they are also on much wider and larger tyres, with far greater
>>> contactr patches.
>>>
>>
>> The concern expressed was about the weight, not the ground pressure.
>> However, the ground pressure is roughly the pressure in the tyres. My
>> first car had a tyre pressure of 20psi. The 2.5PI was 24psi and my
>> current car is 32psi.
>>
> My first had 30 psi. Currently its 32.
>
> But irrelevant to potholes
>

A Challenger 2 tank has about 40% of the ground pressure of my car, but
I doubt it would do my road a lot of good if one ever drove down it.

--
Colin Bignell

On 05/01/2024 12:57, Jethro_uk wrote:
> On Fri, 05 Jan 2024 10:58:22 +0000, Clive Page wrote:
>
>> On 05/01/2024 09:56, Jethro_uk wrote:
>>> [quoted text muted]
>>
>> It seems to be well established that damage to roads is roughly
>> proportional to the fourth power of the weight of the vehicle.
>
> That's one factor. The force of acceleration is another. It creates a
> shear force surely ?

That will only affect the wearing layer. Potholes are formed by faults
deeper in the road structure.

--
Colin Bignell

On 06/01/2024 09:42, Colin Bignell wrote:
> On 06/01/2024 01:15, SteveW wrote:
>> On 05/01/2024 22:27, Colin Bignell wrote:
>>> On 05/01/2024 21:10, SteveW wrote:
>>>> On 05/01/2024 14:44, Colin Bignell wrote:
>>>>> On 05/01/2024 09:56, Jethro_uk wrote:
>>>>>> I recently read a suggestion that some potholes in the UK may be
>>>>>> due to
>>>>>> the action of EV acceleration.
>>>>>>
>>>>>> If true it's a good reason to tax them more.
>>>>>
>>>>> I've not found any reports that support that, but have seen a claim
>>>>> by the suppliers of asphalt that unclassified roads could be in
>>>>> danger from the weight. Classified roads are already built to
>>>>> withstand the weight of HGVs, but unclassified roads, which account
>>>>> for about 60% of the network, are not built to the same standards
>>>>> and some could be at risk from the weight.
>>>>
>>>> Or MG4 is less than 15% heavier than our Zafira, that should have
>>>> little effect on any properly built and maintained road.
>>>
>>> Unclassified roads, such as residential streets, would have been
>>> built to suit the traffic of the day and since then have usually had
>>> little more maintenance than the occasional replacement of the
>>> wearing surface. My road was built in 1931. How do your cars compare
>>> for weight with cars from the 1930s?
>>
>> They probably compare pretty well with narrow wheeled carts and the
>> remaining solid tyred wagons - especially steam wagons.
>
> Those would be using the same roads as today's HGVs and those roads are
> not expected to cause any problems. It is country lanes and residential
> roads that they are worried about. Simply looking at my own vehicle
> history shows the way that vehicle weights have grown. My first car, a
> medium sized saloon, made in 1959, weighed about 16cwt. By the 1970s, I
> was driving a Triumph 2.5pi, which was a big car for its day and that
> weighed in at 1.2 tonnes. My current vehicle is half a tonne heavier
> than that. Your MG4 may only be 15% heavier that your Zafira, but they
> are both a lot heavier than the cars these roads were built for and that
> 15% could be the straw that breaks the camel's back.
>
>
And there are now well over 30 million cars on the road and
a similar increase in HGV's which are now 44 tonnes too (plus
a lot of overweight ones sneaking across from Ireland to the
EU via UK roads) and people are driving much higher mileages
in their cars to commute to distant employment.

There were plenty of old B&W films on TV over christmas (and
every day on TPTV) where the lack of cars on the roads of
places like London is quite a reminder.

On Sat, 06 Jan 2024 20:42:03 +1100, Colin Bignell
<cpb@bignellremovethis.me.uk> wrote:

> On 06/01/2024 01:15, SteveW wrote:
>> On 05/01/2024 22:27, Colin Bignell wrote:
>>> On 05/01/2024 21:10, SteveW wrote:
>>>> On 05/01/2024 14:44, Colin Bignell wrote:
>>>>> On 05/01/2024 09:56, Jethro_uk wrote:
>>>>>> I recently read a suggestion that some potholes in the UK may be
>>>>>> due to
>>>>>> the action of EV acceleration.
>>>>>>
>>>>>> If true it's a good reason to tax them more.
>>>>>
>>>>> I've not found any reports that support that, but have seen a claim
>>>>> by the suppliers of asphalt that unclassified roads could be in
>>>>> danger from the weight. Classified roads are already built to
>>>>> withstand the weight of HGVs, but unclassified roads, which account
>>>>> for about 60% of the network, are not built to the same standards
>>>>> and some could be at risk from the weight.
>>>>
>>>> Or MG4 is less than 15% heavier than our Zafira, that should have
>>>> little effect on any properly built and maintained road.
>>>
>>> Unclassified roads, such as residential streets, would have been built
>>> to suit the traffic of the day and since then have usually had little
>>> more maintenance than the occasional replacement of the wearing
>>> surface. My road was built in 1931. How do your cars compare for
>>> weight with cars from the 1930s?
>> They probably compare pretty well with narrow wheeled carts and the
>> remaining solid tyred wagons - especially steam wagons.
>
> Those would be using the same roads as today's HGVs and those roads are
> not expected to cause any problems. It is country lanes and residential
> roads that they are worried about. Simply looking at my own vehicle
> history shows the way that vehicle weights have grown. My first car, a
> medium sized saloon, made in 1959, weighed about 16cwt. By the 1970s, I
> was driving a Triumph 2.5pi, which was a big car for its day and that
> weighed in at 1.2 tonnes. My current vehicle is half a tonne heavier
> than that. Your MG4 may only be 15% heavier that your Zafira, but they
> are both a lot heavier than the cars these roads were built for

The roads weren't built for the weight of the current cars at the time.

They were always built for the trucks seen at the time, even
with unregulated roads because they used to have trucks
delivering coal and then later heating oil etc and removal
vans and cranes etc for some building work and trucks
loaded with bricks etc.

> and that 15% could be the straw that breaks the camel's back.

Nope, roads don't work like that.

On Sat, 06 Jan 2024 23:19:39 +1100, The Natural Philosopher
<tnp@invalid.invalid> wrote:

> On 06/01/2024 11:24, SteveW wrote:
>
>> But they are also on much wider and larger tyres, with far greater
>> contactr patches.
>>
> In the context of potholes, this is completely irrelevant

No its not when considering if some types
of CARS produce more potholes than others.

On Sun, 07 Jan 2024 00:01:07 +1100, Fredxx <fredxx@spam.invalid> wrote:

> On 06/01/2024 12:19, The Natural Philosopher wrote:
>> On 06/01/2024 11:24, SteveW wrote:
>>
>>> But they are also on much wider and larger tyres, with far greater
>>> contactr patches.
>>>
>> In the context of potholes, this is completely irrelevant
>
> Are you saying the stress placed on a road doesn't matter when it comes
> to forming potholes?

He is essentially saying that its the axle load that bends
and cracks the road surface and lets water in. While that
is true with trucks, it isnt true of cars.

> Did you do a course in art perchance? Engineering is certainly not your
> forte.

His problem has always been ear to ear dog shit, not any course he did.

On Sun, 07 Jan 2024 00:13:14 +1100, Colin Bignell
<cpb@bignellremovethis.me.uk> wrote:

> On 06/01/2024 11:24, SteveW wrote:
>> On 06/01/2024 09:42, Colin Bignell wrote:
>>> On 06/01/2024 01:15, SteveW wrote:
>>>> On 05/01/2024 22:27, Colin Bignell wrote:
>>>>> On 05/01/2024 21:10, SteveW wrote:
>>>>>> On 05/01/2024 14:44, Colin Bignell wrote:
>>>>>>> On 05/01/2024 09:56, Jethro_uk wrote:
>>>>>>>> I recently read a suggestion that some potholes in the UK may be
>>>>>>>> due to
>>>>>>>> the action of EV acceleration.
>>>>>>>>
>>>>>>>> If true it's a good reason to tax them more.
>>>>>>>
>>>>>>> I've not found any reports that support that, but have seen a
>>>>>>> claim by the suppliers of asphalt that unclassified roads could be
>>>>>>> in danger from the weight. Classified roads are already built to
>>>>>>> withstand the weight of HGVs, but unclassified roads, which
>>>>>>> account for about 60% of the network, are not built to the same
>>>>>>> standards and some could be at risk from the weight.
>>>>>>
>>>>>> Or MG4 is less than 15% heavier than our Zafira, that should have
>>>>>> little effect on any properly built and maintained road.
>>>>>
>>>>> Unclassified roads, such as residential streets, would have been
>>>>> built to suit the traffic of the day and since then have usually had
>>>>> little more maintenance than the occasional replacement of the
>>>>> wearing surface. My road was built in 1931. How do your cars compare
>>>>> for weight with cars from the 1930s?
>>>>
>>>> They probably compare pretty well with narrow wheeled carts and the
>>>> remaining solid tyred wagons - especially steam wagons.
>>>
>>> Those would be using the same roads as today's HGVs and those roads
>>> are not expected to cause any problems. It is country lanes and
>>> residential roads that they are worried about. Simply looking at my
>>> own vehicle history shows the way that vehicle weights have grown. My
>>> first car, a medium sized saloon, made in 1959, weighed about 16cwt.
>>> By the 1970s, I was driving a Triumph 2.5pi, which was a big car for
>>> its day and that weighed in at 1.2 tonnes. My current vehicle is half
>>> a tonne heavier than that. Your MG4 may only be 15% heavier that your
>>> Zafira, but they are both a lot heavier than the cars these roads were
>>> built for and that 15% could be the straw that breaks the camel's back.
>> But they are also on much wider and larger tyres, with far greater
>> contactr patches.
>>
>
> The concern expressed was about the weight, not the ground pressure.
> However, the ground pressure is roughly the pressure in the tyres. My
> first car had a tyre pressure of 20psi. The 2.5PI was 24psi and my
> current car is 32psi.

It isnt the tire pressure that cracks the road surface
and lets the water in and produces the pot hole.

And truck tires are much higher pressure than car tires.