Kilometres or miles

Commuting, Day rides, Audax, Incidents, etc.
whoof
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Re: Kilometres or miles

Postby whoof » 11 Jun 2020, 11:05am

Mick F wrote:Having spent much of my professional career in ships, we used Nautical Miles and Cables (ten cables to the NM) we also used Data Miles and Radar Miles.

One of my jobs was maintaining the weapons radars which were made by Selinia ...... and Italian company, so the readouts on the display were in Kilometres. Good job the weapons system was computer driven, and everything was converted so all the equipments could talk to each other.

I maintained the computer suit too.

There are different nautical miles. The international one is exactly 1852m. The uk and US had longer ones that were different from each other.
One of the problems a mixing metric and imperial measurements, even if it is carried out by computer is it depends on the inputted data and how it's been programmed. NASA have had a couple of incidents where they have had a probe slam into a planet and a satellite collide with rather than dock with another due to using mixtures in units systems. It's cost hundreds of millions of dollars in losses.
I've calibrated ship's gyro-compass and verified ship's gps systems as well as providing positional reports and services for off shore facilities.

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[XAP]Bob
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Re: Kilometres or miles

Postby [XAP]Bob » 11 Jun 2020, 11:15am

Peter F wrote:
[XAP]Bob wrote:The mile is metric as well, it’s only a conversion factor.

The reason it isn’t changed is the cost of changing every road sign.


No it's not metric. The fact you need a conversion factor tells you that :lol:



Yes it is, this is a US centric video, but the same applies
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mattsccm
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Re: Kilometres or miles

Postby mattsccm » 11 Jun 2020, 11:33am

Miles. our road signs are in miles so not to use would be daft.
Km in cycling comes from 2 sources.
1. The audax scene where the tradition has come from across the channel. Quite how this took over from traditional events such as 100 in 8 I don't know. Promotion I guess.
2. The press. Cycling magazines and nowadays websites all want to pretend that they are the next best thing to racing in the TdF or riding round the world. Its trendy and all about cycling being new and exciting. Hence the reason why all those newcomers to the sport use Km. Sportives etc use Km so that they can pretend that they are bigger, better, harder than they really are. 100 k should perhaps be said 100 km.(can't put the km in a whispper here.) A modern in Km century sounds better than 62.whatever miles. Cynical me? :D

In the real world I find a mix of metric and imperial works best.
I don't need 1/16th of an inch, a mm is good enough. Equally a cm is handy but then so is an inch as it is more useful that 2.54 cm. So is a foot which is a nice step before a metre which might as well be a yard.
As a size 8 welly is also a foot or near enough to build a shed or cut fire wood so that also works. 6" is the distance from the tip of my outstretched thumb across my fist to the base of my little finger. Other body parts can be used to measure as well. :wink:

eileithyia
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Re: Kilometres or miles

Postby eileithyia » 11 Jun 2020, 12:18pm

Miles.

Kilometers are used for Audax but not sure they have taken over from the old 50 in 4 100 in 8 events. Around here they tend to be organised and ridden by the race fraternity as early season training rides.....

Audax events are available all year around..... with varying distances.

Must admit I tend to use both... though I ride with miles on my garmin.... my other half swaps it around but I tend to leave it set to miles.... working out the distances helps to exercise my brain....
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CJ
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Re: Kilometres or miles

Postby CJ » 11 Jun 2020, 12:59pm

Peter F wrote:As a cyclist and a driver...no. 60kph is ludicrously slow. They've just lowered a NSL road near to where I live to 40mph and it is just a bit silly really.

You are the silly one. Most human beings can just about cope with differences of speed of up to 20mph. Closing speeds much higher than that do not allow enough reaction time for the average not-so-very-attentive driver to slow sufficiently, or take avoiding action. (Yes it would be all very well if driving were restricted to those with the reactions and training of a fighter pilot, but that aint never going to happen.) That is why nothing slower than 50mph is allowed on 70mph motorways and why twenty's plenty in places where quasi-static pedestrians are likely to wander into the road.

So how fast do you think you can cycle? Most people can do 10mph most of the time, so a speed limit of 30mph on roads where bikes mix with cars is quite safe - except on the up-side of steep hills, where a cycle-lane or separate uphill-only cycle-path is advisable. Fast cyclists can often maintain something like 20mph, so they at least should be safe enough on 40mph roads, but higher limits than that are what make rural roads three times as lethal for cyclists than urban roads (see page 9). A previous version of the DfT factsheet I linked to there, separated out rural main roads, where very few cyclists dare to ride, but those who do (presumably only the most serious, fastest and skillful cyclists) are nevertheless 20 to 30 times more likely to be killed per mile travelled, than ordinary Joe Public riding on minor roads in towns (I can't find that one now, but CUK will have it somewhere).
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rfryer
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Re: Kilometres or miles

Postby rfryer » 11 Jun 2020, 1:03pm

I've recently switched from miles to kilometers for cycling. The main reason was that I enjoy watching televised competitive cycling, where all the speeds and distances are reported in kilometers. I find that it spoils the enjoyment if I'm constantly doing mental arithmetic rather than simply being able to relate those numbers to my own experience.

Driving, though, is definitely in statute miles.

Peter F
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Re: Kilometres or miles

Postby Peter F » 11 Jun 2020, 1:07pm

Vorpal wrote:
Peter F wrote:
Campag wrote:
Absolutely - 30mph speed limits would become 30kph or 'twenty is plenty', country roads would be 60kph, still too fast in many circumstances but better than 60mph. Safety, fuel saving and therefore less Co2, friendlier environment for cycling and walking.


As a cyclist and a driver...no. 60kph is ludicrously slow. They've just lowered a NSL road near to where I live to 40mph and it is just a bit silly really.

Actually, that would put British speed limits more in line with other countries that have very low KSI / million km, such as the Netherlands, Denmark, Sweden, Norway, etc.


According to data I can find only Sweden has safer roads than the UK.

https://www.worldlifeexpectancy.com/cau ... y-country/

In general we don't have unsafe roads in this country, in fact we have some of the safest roads in the world.

rfryer
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Re: Kilometres or miles

Postby rfryer » 11 Jun 2020, 1:10pm

CJ wrote:Most human beings can just about cope with differences of speed of up to 20mph. Closing speeds much higher than that do not allow enough reaction time for the average not-so-very-attentive driver to slow sufficiently, or take avoiding action.

Where does this come from? The number of times I've been passed by drivers with a higher closing speed than this must be in the thousands. Am I monumentally lucky in only encountering above average drivers?

Peter F
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Re: Kilometres or miles

Postby Peter F » 11 Jun 2020, 1:23pm

rfryer wrote:
CJ wrote:Most human beings can just about cope with differences of speed of up to 20mph. Closing speeds much higher than that do not allow enough reaction time for the average not-so-very-attentive driver to slow sufficiently, or take avoiding action.

Where does this come from? The number of times I've been passed by drivers with a higher closing speed than this must be in the thousands. Am I monumentally lucky in only encountering above average drivers?


I'm suspicious of that statement too.
I have read that young children cannot accurately judge a cars approach once it gets above 20mph, but nothing in connection to adults.

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The utility cyclist
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Re: Kilometres or miles

Postby The utility cyclist » 11 Jun 2020, 1:45pm

kwackers wrote:
The utility cyclist wrote:Why change something that isn't broken?

Because it simply doesn't fit a lot of things anymore.

It's the 21st century, science is a bigger part of our lives than ever.
SI units are metric. Science is metric. Calculators are base 10.

If I was being fussy I'd argue that nautical miles make more sense - at least they're related to something.

Anyway - I doubt anyone really cares.
We're going metric. The kids use metric, it's only the fossils that have trouble and they'll be gone soon enough.

What doesn't it "fit"?
We have speedometers/odometers in miles/miles per hour, we have speed signs in miles per hour, we have signposts in miles, it works perfectly fine.
As I already said, metric is fine if you want to work from a scientific POV but for most of life there's absolutely no need for it and imperial works, not fine, it simply works and is easy.
I use metric, not through choice at times but was taught both at school so from that it makes no odds, however for every day stuff there's zero reason to change to metric and it would be inordinately expensive.
Would you rather spend hundreds of millions on training nurses and doctors, paying for social care within community or changing for change sake?
If you'd rather spend taxpayers money on changing to a system that isn't needed then that's the wrong answer!

And less of the age related slur, it would seem some don't have the ability to see things for what they are and can only see one route without being able to give a valid/viable reason to change never mind it being massively costly :roll:

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Re: Kilometres or miles

Postby Vorpal » 11 Jun 2020, 2:03pm

Peter F wrote:
Vorpal wrote:
Peter F wrote:
As a cyclist and a driver...no. 60kph is ludicrously slow. They've just lowered a NSL road near to where I live to 40mph and it is just a bit silly really.

Actually, that would put British speed limits more in line with other countries that have very low KSI / million km, such as the Netherlands, Denmark, Sweden, Norway, etc.


According to data I can find only Sweden has safer roads than the UK.

https://www.worldlifeexpectancy.com/cau ... y-country/

In general we don't have unsafe roads in this country, in fact we have some of the safest roads in the world.

I didn't suggest otherwise. By saying *other* countries with very low KSI... I implied that the UK has very low KSI / million km. Is there some reason that we shouldn't strive to improve that?
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Peter F
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Re: Kilometres or miles

Postby Peter F » 11 Jun 2020, 2:05pm

kwackers wrote:
The utility cyclist wrote:Why change something that isn't broken?

Because it simply doesn't fit a lot of things anymore.

It's the 21st century, science is a bigger part of our lives than ever.
SI units are metric. Science is metric. Calculators are base 10.

If I was being fussy I'd argue that nautical miles make more sense - at least they're related to something.

Anyway - I doubt anyone really cares.
We're going metric. The kids use metric, it's only the fossils that have trouble and they'll be gone soon enough.


As someone with a science and engineering background, metric is vastly superior to imperial. Even just the fact that everything is to the base 10 makes is so much better to use.
Yes, I'm used to distances in miles and speed in mph when I'm out and about, but as soon as it comes to doing a calculation km is a much better unit.
I still have my Strava set in miles, but only through habit.

99.9%certain
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Re: Kilometres or miles

Postby 99.9%certain » 11 Jun 2020, 2:06pm

Miles in the UK,KMs in Europe.No big deal as I can convert in my head.When in Mallorca or France I will convert a sign to miles automatically.it's just a subconscious thing.

Peter F
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Re: Kilometres or miles

Postby Peter F » 11 Jun 2020, 2:08pm

Vorpal wrote:
Peter F wrote:
Vorpal wrote:Actually, that would put British speed limits more in line with other countries that have very low KSI / million km, such as the Netherlands, Denmark, Sweden, Norway, etc.


According to data I can find only Sweden has safer roads than the UK.

https://www.worldlifeexpectancy.com/cau ... y-country/

In general we don't have unsafe roads in this country, in fact we have some of the safest roads in the world.

I didn't suggest otherwise. By saying *other* countries with very low KSI... I implied that the UK has very low KSI / million km. Is there some reason that we shouldn't strive to improve that?

No, I just don't believe that drastically cutting all speed limits is the way to do it.
Making every mph a kph is a reduction of 38%, so significant and in many cases unnecessary.
Last edited by Peter F on 11 Jun 2020, 2:20pm, edited 1 time in total.

Bmblbzzz
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Re: Kilometres or miles

Postby Bmblbzzz » 11 Jun 2020, 2:18pm

Mick F wrote:Having spent much of my professional career in ships, we used Nautical Miles and Cables (ten cables to the NM) we also used Data Miles and Radar Miles.

One of my jobs was maintaining the weapons radars which were made by Selinia ...... and Italian company, so the readouts on the display were in Kilometres. Good job the weapons system was computer driven, and everything was converted so all the equipments could talk to each other.

I maintained the computer suit too.

Nautical kilometres or Italian kilometres? :wink: