Relationship between speed and safety

[Angus]

This hasn't been aired on the forum for some time. Lots of newbie MPs were recently elected to power. I wonder if one or two might stake their claim to political immortality or even usefulness by championing the 'Safe Speed' cause?

Unfortunately, since Paul's death in 2007, no-one has stepped up to challenge the likes of brake and their propaganda in the way that he did.

Lots of MPs have taken the IAM test (local PR). At least one has taken the High Performance Course.

[Garrison]

When one consider risk, one have to separately consider 1) the probability and 2) the magnitude of events. For example, the risk is the same whether you have 1) a 10% chance of losing (or winning) 50% or 2) a 50% chance of losing (or winning) 10%.

So what is your preference? Would you rather have loads of near-misses or one big "off"?

I guess most politicians think people would prefer the former (including myself) - i.e. high probability of low speed impacts and low probability of high speed impact. Given how statistics are reported and how media interprets them, more attention is placed on the total number of fatalities or serious injuries than total cost of minor injuries and insurance costs.

Back to your question on the correlation between speed and safety, my guess are

1) positively correlated between speed and the magnitude of the crashes in terms of human costs, especially on a case by case basis
2) negatively correlated between speed and the probability of the crashes, in terms of insurance costs on a overall basis

Now, any mathematician here willing to build a model to see if the net-net effect has changed over the last 100 years?

[TripleS]

...My attitude can probably be deduced from the fact that my 7 year old (who's commentary isn't bad) refers to NSL signs as "Full speed ahead signs".

- at least he didn't say....G...L...F....

Maybe some people still think of them as derestriction signs....

I really don't care for this tendency for officialdom to change things without my prior agreement: it's simply not on.

Best wishes all,
Dave.

[petes]

I'm with Martin on this one.

Although a speed limit should reflect areas of increased danger, and generally I suppose they do, the fact of the matter is that a SAFE speed will vary from minute to minute due to the fluctuation in hazard density.

There is also the mindset that " I'm keeping to the speed limit so I'm safe." This has been borne out on several occasions by learners who I have taken down a short, 400yds long lane that links two 30mph roads. The only reason that this lane is NSL is the fact that it has no street lamps.
The usual comment is " This road should have a 30 limit " despite the fact that you are unlikely to excede 20 mph because of the narrowness, road surface, and visibility etc.

The important thing is that drivers drive at a speed appropriate to conditions.

As an extension to this statement, it's probably reasonable to say: "The important thing is that drivers drive at a speed appropriate to conditions, but not exceeding the speed limit for that particular section of road".

Whilst it's entirely debatable whether some speed limits are appropriate, it's less subjective whether they should be obeyed.

[akirk]

As an extension to this statement, it's probably reasonable to say: "The important thing is that drivers drive at a speed appropriate to conditions, but not exceeding the speed limit for that particular section of road".

Whilst it's entirely debatable whether some speed limits are appropriate, it's less subjective whether they should be obeyed.

now you are getting into philosophical discussion...
- if law is simply a construct of mankind
- and law is only temporary based on the personal perspectives of those in power and creating the law
- and we can all quote examples of laws in countries around the world which should not be obeyed
- at what point / who decides which laws should / shouldn't be obeyed...

is it down to moral outrage of the chattering middle classes
is it down to some ethical or moral framework underpinning our society (does that even exist any more?)
is it down to cold clear scientifically based fact

there is an argument that says that our political system is flawed and based on a minority influencing / ruling the rest - so is law the construct of a minority and therefore by its nature might not be the majority view?

could you free the country of law and see how people behave, and then map behaviour to law to determine the most accurate pattern of behaviour desired by the people?

is it morally reprehensible to drive at 60 in a 30 past a school - most would argue yes, is it the same issue driving at 60 in a 30 zone just outside a village with no turnings / no houses / no school children / no hazards? if so, why? - if not then the law is not consistent / absolute...

is a 30 / 40 / 50 zone which has been put in for politial reasons (avoid having to repair roads / anti motoring brigade in power in the local council / etc.) and more or less law than a zone set up correctly based on an analytical approach around safety and hazards?

is a speed marking system which is no longer consistent, (but based on politics, not genuine need) one which should be observed?

lots of questions - but what is clear above all else is that speed & the law in a political context is not a simple black and white question which all should mindlessly accept and obey without any thinking...

Alasdair

[petes]

As an extension to this statement, it's probably reasonable to say: "The important thing is that drivers drive at a speed appropriate to conditions, but not exceeding the speed limit for that particular section of road".

Whilst it's entirely debatable whether some speed limits are appropriate, it's less subjective whether they should be obeyed.

now you are getting into philosophical discussion...
- if law is simply a construct of mankind
- and law is only temporary based on the personal perspectives of those in power and creating the law
- and we can all quote examples of laws in countries around the world which should not be obeyed
- at what point / who decides which laws should / shouldn't be obeyed...

is it down to moral outrage of the chattering middle classes
is it down to some ethical or moral framework underpinning our society (does that even exist any more?)
is it down to cold clear scientifically based fact

there is an argument that says that our political system is flawed and based on a minority influencing / ruling the rest - so is law the construct of a minority and therefore by its nature might not be the majority view?

could you free the country of law and see how people behave, and then map behaviour to law to determine the most accurate pattern of behaviour desired by the people?

is it morally reprehensible to drive at 60 in a 30 past a school - most would argue yes, is it the same issue driving at 60 in a 30 zone just outside a village with no turnings / no houses / no school children / no hazards? if so, why? - if not then the law is not consistent / absolute...

is a 30 / 40 / 50 zone which has been put in for politial reasons (avoid having to repair roads / anti motoring brigade in power in the local council / etc.) and more or less law than a zone set up correctly based on an analytical approach around safety and hazards?

is a speed marking system which is no longer consistent, (but based on politics, not genuine need) one which should be observed?

lots of questions - but what is clear above all else is that speed & the law in a political context is not a simple black and white question which all should mindlessly accept and obey without any thinking...

Alasdair

I suppose the bottom line is, no, you don't have to observe rules and laws that you don't agree with. However, they are present in black and white, so if you choose not to abide by them, but have little justification in complaining when you receive a punishment in accordance with your infringement.

I would agree that someone travelling at 80mph instead of 70mph on a quiet motorway, does not represent any danger to themselves or others. They are still breaking the law though, and have no right to cry "foul play" if they were to receive a fixed penalty notice for doing so. It's a calculated risk that they choose to take.

[jont]

https://www.gov.uk/government/uploads/s ... s-2012.pdf
"On motorways, 48 per cent of cars exceeded the 70 mph
speed limit in 2012, a decrease of one percentage point from
2011.
 Eighty two per cent of articulated heavy goods vehicles
exceeded their 50 mph speed limit on dual carriageways and
73 per cent exceeded their 40 mph limit on single
carriageways. "
At the point a majority of the population are acting as criminals, one has to question whether the law is really still appropriate (and given our justice system cannot actually cope with the number of people caught - hence the option of FPNs, doesn't that also tell you the system is wrong?)

Can you name any other area of law (other than tax avoidance) where it's expected that normal behaviour is right on the edge of illegality?

Our problem is that as a society we have become obsessed with measurement. Instead of measuring what's valuable, we now value things that are trivially measurable (see also why the eduction, NHS and policing as a whole are broken )


We have also now created an entire industry that needs speeding motorists to continue to justify it's existence. Is that really something desirable?

[petes]

We have also now created an entire industry that needs speeding motorists to continue to justify it's existence. Is that really something desirable?

You seem to be forgetting that the speeding motorist is not a victim! Nobody's forcing you to speed, or even drive at all for that matter! You can't choose to do so, in full knowledge of the laws that are in existence, then complain that you're expected to remain within those parameters!

It's bit like the old man who buys a house next to an airport, then writes to the council, complaining of aircraft noise!

[jont]

We have also now created an entire industry that needs speeding motorists to continue to justify it's existence. Is that really something desirable?

You seem to be forgetting that the speeding motorist is not a victim! Nobody's forcing you to speed, or even drive at all for that matter! You can't choose to do so, in full knowledge of the laws that are in existence, then complain that you're expected to remain within those parameters!

It's bit like the old man who buys a house next to an airport, then writes to the council, complaining of aircraft noise!

Is a speed camera that catches no motorists seen as a success or a failure?

[petes]

We have also now created an entire industry that needs speeding motorists to continue to justify it's existence. Is that really something desirable?

You seem to be forgetting that the speeding motorist is not a victim! Nobody's forcing you to speed, or even drive at all for that matter! You can't choose to do so, in full knowledge of the laws that are in existence, then complain that you're expected to remain within those parameters!

It's bit like the old man who buys a house next to an airport, then writes to the council, complaining of aircraft noise!

Is a speed camera that catches no motorists seen as a success or a failure?

If people are speeding at the site of the camera and it doesn't catch them, then it's a failure.
If it doesn't catch anyone because they are no longer speeding as a result of its presence, then it is a success.

I sense you will find a way of contradicting this or finding fault in what I have said though.

[Gareth]

You seem to be forgetting that the speeding motorist is not a victim!

If a speed limit is reduced because a minority of drivers are unsafe, then the majority of drivers are victims because they are being inconvenienced.

[petes]

You seem to be forgetting that the speeding motorist is not a victim!

If a speed limit is reduced because a minority of drivers are unsafe, then the majority of drivers are victims because they are being inconvenienced.

I'd agree with that. The best way forward in such circumstances is to campaign for a reinstatement of the original limit. Ignoring it merely puts us at risk of getting rozzered, then we really are the victims!

[petes]

I'd agree with that. The best way forward in such circumstances is to campaign for a reinstatement of the original limit. Ignoring it merely puts us at risk of getting rozzered, then we really are the victims!

Good luck with that... when I see the dark overlord with a pair of ice skates, I'll know someone has been successful. No politician is going to do something that might increase the risk of death.

I thought the general consensus of opinion on this forum (or at least this thread) was that reducing speed does not increase safety?

[jont]

I'd agree with that. The best way forward in such circumstances is to campaign for a reinstatement of the original limit. Ignoring it merely puts us at risk of getting rozzered, then we really are the victims!

Good luck with that... when I see the dark overlord with a pair of ice skates, I'll know someone has been successful. No politician is going to do something that might increase the risk of death.

Or even something that might be perceived to increase the risk of death. When you present a councillor with a DfT document that says "inappropriately low limits don't work" and they say "any speed limit reduction is a good thing" and smacking them round the face with an NSL sign would count as assault, what can you do?

[petes]

When you present a councillor with a DfT document that says "inappropriately low limits don't work" and they say "any speed limit reduction is a good thing" and smacking them round the face with an NSL sign would count as assault, what can you do?

Out of interest, would you propose as a basic structure for our national speed limits? Obviously there would be exceptions but I'm assuming you would consider our basic 30/60/70mph system to be inappropriate. What starting points for each main category of road would you like to see in place?