Variable speed limits on the M25

But the pedestrian stepping out into the middle of road without looking doesn't cause any part of the crash?

 

By far the biggest cause of road accidents is driver/rider error or reaction, which causes 68% of all crashes.

The top ten most common causes of traffic accidents are:

• Failed to look properly 35%
• Failed to judge other persons's path or speed 18.9%
• Careless, reckless or in a hurry 16.2%
• Loss of control 14.7%
• Poor turn or manoeuvre 14.1%
• Travelling too fast for the conditions 10.2%
• Slippery road due to weather 10.1%
• Pedestrian failed to look properly 7.2%
• Sudden braking 7.2%
• Following too close 6.7%

 

A child is unable to accurately assess risk until they are about 10 years old. They are also very poor at estimating speed. In an urban situation a child crossing the road within 100 feet of a moving car is not, therefore, an unlikely scenario.

As explained above, if you are doing 40mph that child will die, at 25mph they would not only live, you would probably stop before even hitting them.

If the child cannot comprehend risk it cannot be their fault (perhaps it is their parents for letting them cross the road). Primarily it is your speed that will kill them.

When urban speed limits have been reduced fatalities, especially child fatalities, have been reduced. This is a fact.

Do you really need to be anywhere that urgently that it is worth risking a child's life?

 

All one and the same with the underlined, that's exactly 50% and I'd add most of "loss of control"

 

Following too closely is related to keeping a good gap to the car in front - not directly linked to speed because you can still tailgate in a 20mph zone.

Sudden Braking again is about slamming brakes on rather than gentle braking - they could just be slowing at a junction, so not to do with speed.

I would agree that 36.2% are to do with speed.

So, again, as you have pointed out too, speed is not the main causes of accidents.

 

You should be prepared to have to slow down or stop at all times and at whatever speed. If you can't then you are going too fast for the conditions.

It's quite simple really.

 

Accident data can have more than one cause attributed to each collision and so you can't just add up those percentages.

Again, speed is relevant in every context since it affects both likelihood and severity.

Drivers make errors, they always will. Pedestrians, cyclists, motorcyclists will always make errors. Collisions will always happen, and these generally happen around junctions. Therefore the solution is to separate each mode. Pedestrians, cyclists, mobility scooters etc need to have the most direct, traffic free routes, and motor vehicles should be doing the majority of their journey on motorways and distributors.

20mph is only an issue if it's a large part of your journey. Which it shouldn't be, but that needs political will to reclassify roads to a modern standard and a big push to leave the car at home for journeys under 5 miles.

 

He should have got out and failed the other driver retrospectively.

 

Not sure why people are trying to conflate cause and effect.

It's a reality that accidents happen. Speed limits are created on that basis. Travelling 100 mph in a 30 zone might not be the cause of the accident if a silly child runs out into the road, but it's almost certainly the reason the kid that got hit died.

Speed is simply a significant mortality multiplier. While it may not always be the root cause of an incident (although it can be and is) higher speed makes every accident that happens worse. That's the justification for limitations. There may be fewer accidents on motorways than side roads, but the ones that do happen are significantly worse.

I've seen a 70 mph crash firsthand. The subsequent shunting and pile-ups are devastating in a way you just don't see at lower speeds.

 

You haven't got this one right I'm afraid. The reason lower speed deaths are up is because there are more accidents on urban and rural roads than before, nothing to do with higher speeds being safer. The argument that higher speed collisions will cause a greater likelihood of death is indisputable.

 

Because you guys are just trying to simplify it all. Obviously a crash into a pedestrian or wall is more dangerous at higher speeds. But that doesn't mean driving at reduced speed is always better or safer.

As an example, driving at 30mph on open country roads is likely to encourage other drivers to try and overtake. Whereas someone driving progressively at 50 less so. Another, someone driving at a slower speed than the rest of the traffic on any traffic is more dangerous than keeping up.

There are a host of other examples.

 

I dispute that.

If I was doing 70 and crashed into the back of another car, I would prefer it to be doing 60 than 30.

 

If you crash into the back of someone doing 30 doing 70 yourself you've probably made a fairly major driving error. I don't think the onus would be on the car in front to speed up.

 

If we are talking "fault" then that is a different discussion.

I was just pointing out that high speed collisions are not always more dangerous - something you said was indisputable.

 

Really?

I think it's quite clear that I'm talking about an object at a FIXED speed (or static) will always be worse off when hit at a faster speed, and in the case of a pedestrian more likely to die.

Be obtuse if it helps!

 

And if they were doing 30 and had a car going 70 crash into them, they'd undoubtedly want that car going 40 or slower...

Are you also then saying that you'd rather hit a kid at 40 that is running away from you at 5mph, than hit them at 20 that's running towards you?

Can't believe this post is actually getting a response.

 

i gave up a day or so ago
nonsense

 

Just incase nobody gave the information earlier.. as I understand it.

Traditional gantry electronic speed signs are NOT inforceable, they are an advisary notice.

The NEW ones which show the red border around the speed ARE inforceable. These are the ones appearining on the M25 and the M1

 

Its just a healthy debate my friend :drinking:

This is a forum after all!

 

Am I being obtuse because I am considering other MOVING road users?

Surely it is sensible.

 

Can't like on this bloody tapatalk, so here's a manual like

 

do you drive at 30 or 40 on a dual carriageway or motorway because it is safer?

I would have thought it was safer to drive faster.

 

Something I really would like to see are the cameras used to prosecute poor/dangerous driving. A good example is the southbound A1, notably after the M25 turn-off. The lanes are narrow and the amount of drivers pootling along at 50(ish) mph in the 2nd ("overtaking") lane is frightening, particularly as it's merging with traffic coming down the slip-road "getting up to speed" and you've got the Trotter's Bottom turn-off about a mile down the road with lots of traffic pulling out, from a standing start, into traffic travelling at motorway speeds.

When the revolution come and I'm in charge, I'm going to utilise the space available on the Stirling Corner roundabout in a mass public education exercise. Cameras will catch and record all instances of improper/dangerous lane discipline at this roundabout. First offence: the stocks for a 24 hr period. Subsequent offence: the gibbet - until you've rotted down to skeletal remains. There's space for lots of stocks and gibbets.

 

Cheers IAYS. Perhaps it's my age but I don't remember the gantry speed signs NOT having a red circle around them?

 

http://www.ukspeedtraps.co.uk/stopping.htm

As per the highway code
Speed Distance to Stop / Feet per Second / Car lengths
20 mph 12m 40ft 29.4 ft/sec 4
30 mph 23m 75ft 44.1 ft/sec 6
40 mph 36m 120ft 58.8 ft/sec 10
50 mph 53m 175ft 73.5 ft/sec 14
60 mph 73m 240ft 88.2 ft/sec 20
70 mph 96m 315ft 102.9 ft/sec 26

These were devised in the 60s when most cars had drum brakes, no servo assistance, no anti lock systems or traction control, which are all pretty much standard now.

Might I also point out that UK cars are geared and tuned according to current speed legislation. Any change is speed regulations changes will have an impact on fuel consumption & emissions, people possibly being in a higher gear and hence at a higher rpm. People might need to change gear more regularly also.

My personal opinion is that street design, unnecessary signs etc as well as street parking in urban areas is more of a concern than speeding where accidents are concerned. The various stats previously posted tend to support this.

 

???

You drive as fast as is safe for the current conditions, within the designated limit. Driving 30 or 40 on a motorway is clearly an anomaly.

What about the collisions that occur due to people approaching traffic jams on the motorway too fast? Is it the stopped traffic to blame for going too slow?

Anyway, it's already been established that most accidents occur on urban roads, and the worst fatalities are between cars and motorcycles/cycles/pedestrians, that's the way the thread was going.

Given your apparent penchant for driving fast you can forgive me for assuming you were talking about doing 70 in a cul-de-sac.

 

I think this is an example of what he's talking about:

 

Isn't this about concentration/anticipation rather than speed? If a driver anticipates that the traffic is slowing, he slows to join the queue.

You make it sound like traffic jams suddenly appear like a brick wall.

 

You didn't post twice, does this thread automatically get closed now?!

:whoosh:

 

Again, you are arguing against physics. I can understand why Layton has given up. It is like the climate change debate. It's fine to have your own opinions but you can't have your own facts.

In 2013, 249 people were killed in crashes involving someone exceeding the speed limit (16% of all road deaths) and a further 209 people died when someone was travelling too fast for the conditions.

Stopping distances at 40mph are going to be 3 times the distance than they would be at 20mph whatever tech you have on your car. You will travel the best part of 40 feet before you even hit the breaks and, as per my other post, you will still be travelling in excess of 30mph after 100 feet (Source: McLean AJ, Anderson RWG, Farmer MJB, Lee BH, Brooks CG. Vehicle Speeds and the Incidence of Fatal Pedestrian Collisions - Volume 1. Federal Office of Road Safety, Australia.).

Obviously most accidents happen due to driver error but it's an absolute fact that speed plays a big part in the outcome. There is absolutely no arguments that makes a modicum of sense for increasing urban speed limits but there are plenty of reasons why 30mph or even 20mph is the maximum anyone should travel in an urban area.

Recently there was an air show disaster at Shoreham which killed 11 people and, rightly, made headline news. In the 9 days following this 'national disaster' it is likely that a further 11 people died because of people driving at excessive speed.

I honestly can't understand why people argue for speeding. It really doesn't get you to where you are going much quicker anyway so why risk lives?

 

sydney_horn, out of interest, what is your job?

 

Not arguing for or against just stating some facts. I've actually proposed an enforceable 20mph limit in areas where circumstances dictate. I've proposed a raise to 40 in main busy thoroughfares and I've suggested a raise on Motorways in the UK which are amongst the safest in Europe.

What I do believe is that poor road design and poor use of the roads are more important areas to tackle with regards to road safety than speeding. Speeding is targeted because its easier and generates revenue. I'm not advocating speeding, I'm advocating a more sensible approach to road speed limit categorisation.

As an example a single lane road local to me has a semi rural section with a 50mph limit, it also has a residential section with a 30mph. Every single time without fail, when I drive down that road the car in front is doing 40mph for the whole length of the road. I would argue that is dangerous in both sections as in the 30mph section there is the risk of morons reversing out from their concealed driveways into traffic or kids running into the street so the limit should be 20. On the faster section people are tempted to overtake because drivers in front are not making efficient progress (That's actually a fail on the driving test by the way). I've actually had someone overtake me at 40mph in this section and then realise there was oncoming traffic and there was someone in front of me doing 40mph, luckily I had my head screwed on and slowed to let them in front of me.

 

Which is my point.

Most accidents aren't caused by speeding.

 

I'm a data analyst and modeller.