Motorway 'safe' distance chevrons
Discussion
25NAD90TUL said:
I much prefer to leave a 5 second gap at 50, 7 second gap at 70 etc, imo the chevrons are not far enough apart as others have said, what are they 2 second intervals? Not enough at anything above 30mph imo.
I guess they are there for drivers who have no comprehension of a safe distance, I ignore the chevrons and maintain my own safe distance, I watch the vehicle in front pass a marker, say a bridge, and then count in seconds until I pass the same marker. I did that with an examiner onboard, and specified in commentary that I was 'maintaining a 7 second gap at 70mph', all he said was 'excellent!'
How many times have we all seen drivers less than the two chevrons apart? Me, many.
I hope you never use the overtaking lane... Two seconds is plenty in normal driving conditions.I guess they are there for drivers who have no comprehension of a safe distance, I ignore the chevrons and maintain my own safe distance, I watch the vehicle in front pass a marker, say a bridge, and then count in seconds until I pass the same marker. I did that with an examiner onboard, and specified in commentary that I was 'maintaining a 7 second gap at 70mph', all he said was 'excellent!'
How many times have we all seen drivers less than the two chevrons apart? Me, many.
LordGrover said:
I've understood the sign to keep two chevrons apart:
car > _ > car
it's never felt quite enough which if my maths is correct is the case.
^ that's "one chevron".car > _ > car
it's never felt quite enough which if my maths is correct is the case.
LordGrover said:
So, should it be three chevrons to be more in line with the two second rule?
car > _ > _ > car
^ That's "two chevrons".car > _ > _ > car
LordGrover said:
or have I misinterpreted it all along and it's just poor English and they meant two gaps between chevrons? Even the graphic is ambiguous IMO.
Yeah, it's not massively clear is it? Pretty sure my interpretation is what they meant.25NAD90TUL said:
WinstonWolf said:
I hope you never use the overtaking lane... Two seconds is plenty in normal driving conditions.
Two seconds plenty at 70 mph? If I do use the overtaking lane I hope you're not behind me!
When in France they have a good system where the solid white line at the (off side for us) (near side for them) has a gap in it at the distance of the chevrons they put in the roads here. It is easy to check you have the correct distance from the vehicle in front.....but I never see any frogs obeying it!
The highway code should be used as a general guide only and not fact.....most modern cars on a dry road with good tyres can easily spank those stopping distances, my learners can stop my BMW Mini on 16" tyres on a dry day in a smidgen over 1 car length from 30 mph....where as the highcode suggests it's 6 car lengths.....but there are cars out there that may well take that amount of distance to stop. I have not done an emergency stop from 70 mph owing to "safety" issues, but I bet it's a load less than the HC's 96 odd metres
The highway code should be used as a general guide only and not fact.....most modern cars on a dry road with good tyres can easily spank those stopping distances, my learners can stop my BMW Mini on 16" tyres on a dry day in a smidgen over 1 car length from 30 mph....where as the highcode suggests it's 6 car lengths.....but there are cars out there that may well take that amount of distance to stop. I have not done an emergency stop from 70 mph owing to "safety" issues, but I bet it's a load less than the HC's 96 odd metres
watchnut said:
The highway code should be used as a general guide only and not fact.....most modern cars on a dry road with good tyres can easily spank those stopping distances, my learners can stop my BMW Mini on 16" tyres on a dry day in a smidgen over 1 car length from 30 mph....where as the highcode suggests it's 6 car lengths.....but there are cars out there that may well take that amount of distance to stop. I have not done an emergency stop from 70 mph owing to "safety" issues, but I bet it's a load less than the HC's 96 odd metres
Slight problem being the thinking and reaction time. I would say it stands a chance of being over depending on the driver.One major thing to remember - it doesn't matter how good your brakes are
it all depends on the make and quality of the tyres used and the point at which
the fail to maintain 'grip'. You could have the best brakes in the world but, as
soon as 'grip' is lost they are useless. Before you mention ABS, a few years ago
the bus company I worked for bought a fleet of busses fitted with ABS and they
found an increase in 'minor collisions'. They found that the busses were actually
stopping at a greater distance than a normally braked bus. In the end, all of the
busses were being driven with the ABS turned off. Instructions were given only
to use it when it rained or snowed. This means of driving worked perfectly and
is as far as I know, is still being adhered to to this day.
it all depends on the make and quality of the tyres used and the point at which
the fail to maintain 'grip'. You could have the best brakes in the world but, as
soon as 'grip' is lost they are useless. Before you mention ABS, a few years ago
the bus company I worked for bought a fleet of busses fitted with ABS and they
found an increase in 'minor collisions'. They found that the busses were actually
stopping at a greater distance than a normally braked bus. In the end, all of the
busses were being driven with the ABS turned off. Instructions were given only
to use it when it rained or snowed. This means of driving worked perfectly and
is as far as I know, is still being adhered to to this day.
jules_s said:
This has annoyed me for some time 
>---->
^^^ that is clearly two chevrons
>---->---->
Is clearly three chevrons and is circa 2 seconds at 70mph
Keep two gaps would be a better description, as the gap is the linear measurement!
So what happens when >----> turns into --->- >---->
^^^ that is clearly two chevrons
>---->---->
Is clearly three chevrons and is circa 2 seconds at 70mph
Keep two gaps would be a better description, as the gap is the linear measurement!
Are you still two chevrons apart?
109er said:
One major thing to remember - it doesn't matter how good your brakes are
it all depends on....
....what's behind you.it all depends on....
I recently did some ABS demos in a well known manufactures twin cab 4x4 pick-up. Fully capable of keeping up with the flow in L3 but f
k me it had the stopping ability of a super tanker! I tend to keep clear of these things now.
Toltec said:
So what happens when >----> turns into --->-
Are you still two chevrons apart?
The chevrons are there to define a set distance.Are you still two chevrons apart?
At >----> you are the distance of 2 chevrons apart. So the answer is yes.
As shown here:
It's not showing 3 chevrons, it's showing 2. So >----> not >---->---->
If they wanted people to be 2 gaps apart that's what the sign should say.
Munter said:
The chevrons are there to define a set distance.
At >----> you are the distance of 2 chevrons apart. So the answer is yes.
As shown here:
It's not showing 3 chevrons, it's showing 2. So >----> not >---->---->
Is that sign showing >----> or >---->----? Or something in between?At >----> you are the distance of 2 chevrons apart. So the answer is yes.
As shown here:
It's not showing 3 chevrons, it's showing 2. So >----> not >---->---->
Munter said:
If they wanted people to be 2 gaps apart that's what the sign should say.
I quite agree 
.Munter said:
The chevrons are there to define a set distance.
At >----> you are the distance of 2 chevrons apart. So the answer is yes.
As shown here:
It's not showing 3 chevrons, it's showing 2. So >----> not >---->---->
If they wanted people to be 2 gaps apart that's what the sign should say.
As soon as that car goes over the first chevron though and it's --->- and then you've not kept two chevrons apart. It doesn't say 'at some point in time be 2 chevrons apart'. Still, it should say something where the semantics don't warrant this much discussion!At >----> you are the distance of 2 chevrons apart. So the answer is yes.
As shown here:
It's not showing 3 chevrons, it's showing 2. So >----> not >---->---->
If they wanted people to be 2 gaps apart that's what the sign should say.
0000 said:
As soon as that car goes over the first chevron though and it's --->- and then you've not kept two chevrons apart. It doesn't say 'at some point in time be 2 chevrons apart'. Still, it should say something where the semantics don't warrant this much discussion!
I'll run through this as I "think it" when I see the sign.Keep 2 chevrons apart
I can see the distance between 2 chevrons
I am that distance from the car in front
I am doing as requested
Now I know it should be 2 gaps, so have to override what it's telling me, if I want to do what it asks. It's a rubbish sign in the same vein as the Thank Bake signs.
Turns out it was supposed to be Think Bike. But the bike picture used for the i looked like an a when you're going past at speed. So they took the picture out of the words in the end.
25NAD90TUL said:
simoid said:
Mate, 7 seconds at 70? Seriously? You must be Joe King.
Sure 7 seconds is a large gap, 2 seconds however is woefully inadequate imo. Regarding someone slipping into this gap, part of the reason for doing so might be so that someone can slip into it in an emergency...Including me.Besides if I'm doing 70mph, leaving a large gap, do people think they're going to get to their destination any quicker by driving up my arse or me driving up the car in front's arse? Also the large gap is going to give me somewhere to escape to should you come flying at my rear end. The 'thinking distance' isn't being factored in here either, or are we super human in terms of reaction time? Or is our ABS going to save the day? All I know is that if you hit the heavy iron work on my rear at 70, you would need cutting out of your vehicle at the very least, I would consider being two seconds behind at 70 to be tantamount to tailgating. I'd be more than happy to drop out of the lane in that situation, I've had to untangle the wreckage and view the carnage in too many multi-car pile ups.
What is two seconds at 70 in terms of feet or metres travelled?
Can anyone say what the stopping distance at 70 equates to in seconds travelled at that speed?
25NAD90TUL said:
25NAD90TUL said:
simoid said:
Mate, 7 seconds at 70? Seriously? You must be Joe King.
Sure 7 seconds is a large gap, 2 seconds however is woefully inadequate imo. Regarding someone slipping into this gap, part of the reason for doing so might be so that someone can slip into it in an emergency...Including me.Besides if I'm doing 70mph, leaving a large gap, do people think they're going to get to their destination any quicker by driving up my arse or me driving up the car in front's arse? Also the large gap is going to give me somewhere to escape to should you come flying at my rear end. The 'thinking distance' isn't being factored in here either, or are we super human in terms of reaction time? Or is our ABS going to save the day? All I know is that if you hit the heavy iron work on my rear at 70, you would need cutting out of your vehicle at the very least, I would consider being two seconds behind at 70 to be tantamount to tailgating. I'd be more than happy to drop out of the lane in that situation, I've had to untangle the wreckage and view the carnage in too many multi-car pile ups.
What is two seconds at 70 in terms of feet or metres travelled?
Can anyone say what the stopping distance at 70 equates to in seconds travelled at that speed?
Toltec said:
One more reason for leaving a larger gap to a car you want to pass, but cannot pull over yet, is that you can close that gap when there is space to the left for them to pull into. It does not always work, however if they are paying any attention they will realise you do want to pass and will get on with it so they can pull back out again if required.
I always leave a large gap from the vehicle in front and often find that the driver behind me will leave a similar gap in these circumstances, I don't hold other drivers up because of it, because if one comes too close for my liking I will just drop out of lane, get out of their way in other words, because I want that driver as far away from me as possible for the sake of my own safety.As stated I have used the 2 seconds at 30, 5 seconds at 50 and 7 at 70 with a class 1 police onboard who thought it was an excellent safety margin, those people don't like techniques that upset the flow of traffic, so I'm good with it and will be sticking to it. The frequency of multi-car pile ups on motorways just goes to illustrate that the distances considered safe by some drivers is woefully inadequate.
The mantra 'always being able to stop in the distance that can be seen to be clear' springs to mind.
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