Driving advice: leaving a gap – only a fool breaks the two second rule?

How big a gap do you typically leave between you and the car in front?

The Driving Standards Agency recommends the two-second rule (as in “only a fool breaks the two second rule”).

That equates to
30mph = 26.8 meters
50mph = 44.7 meters
70mph = 62.6 meters

and that’s for “dry conditions”. They say “at least double this in bad conditions” 😯

But that doesn’t seem to be even remotely close to what actually happens on the roads.

We came up the M6 yesterday in smeary rain with quite a lot of surface water and road spray, but even in those conditions the majority of traffic was much much closer than that. And on a couple of occasions I had a car overtake me then pull back in with barely a car length between us, effectively blinding me with spray at 70mph+.

All pretty standard to be honest – but a friend witnessed a fatal accident on the same stretch of the M6 today, so it got me pondering.

I agree, folk just do not do the reasonable gap thing, especially in bad weather.

I try to leave a gap but often it is less than advised, certainly in bad conditions. As you say when you leave a gap someone fills it. Too many cars on roads designed for less traffic with an extremely outdated rail network.

I always give a little extra gap for bigger, faster sports cars.

i quite often recite the ‘only the fool’ rhyme in my head and back off if I’m a little close. Nobody else ever bothers but I’d rather I had the distance that didnt, irrespective of anybody else.

I us d to be an instructor and used “only a **** hits the car in front”.

Dint forget, you ideally want that two second gap front and rear. If you’ve not got it behind, compensate by making it bigger in front.

Good luck making it work though. That 50 limit on the M1 has people driving with slightly more than a cars length between them.

This is a great way for people to demonstrate what stupid, selfish twunts they are.
Of course, they’re like this all the time, but driving is one of the rare chances they get to endanger your life with it.

APF

I’ve pondered this too. It occurred to me if people roughly doubled the gap to be closer to what the Highway Code recommends, we’d effectively half the capacity of our roads at peak time. Then what would happen?

My car has a pop-up display that shows the time gap between me and the car in front. Clearly that demands research:

On the M27, wet or dry, a gap of anything over 0.65 seconds is deemed by the majority of drivers to be fair game to the extent that they won’t even indicate when pulling OUT into it – regardless of difference between their speed and mine when they pull out

Even a single flash of indicator allows instant access to the “gap” even when below the 0.65 second mark. (Note that this flash may be activated once the maneouvre is in process or even completely retrospectively with no change to the absolute priority of the driver in making progress)

Pulling IN for, say, a slip road exit, all bets are off and any gap’s good, I imagine even if it’s a car-length and definitely when you’re braking sharply at the same time (indication optional here (and rare), except for the bird which is a mandatory post-manouvre action)

Two rear end shunts on the A9 around Perth/Dunkeld today. Neither serious happily but was good for showing the kids why you need the gap. Was the fatal on the M6 near Kendal?

For clarity, I’m not claiming perfect STW Driving God status here. Tails accurately summarises my own approach too.

Just interested in other people’s opinions and approaches.

Fatal on M6 southbound between jct 39 & 38 Shap and Tebay.

I find if you’re on a single carriageway road leaving a proper gap will inevitably mean the person behind will start trying to “hurry you up”, and driving even closer, so you end up in a vicious cycle. If I’m driving it’s in a van, so to some extent I can just ignore them, but in a smaller car it could be intimidating.

I think this is a subject where a bit of public education about how big a safe gap actually is would pay off enormously; I think most people just don’t know they’re doing anything wrong…

Typically it seems to be people who live their lives 10 minutes late 🙁

I try to leave a suitable gap…probably not as large as the recommended highway code distances, but a decent amount.

Problem is that people just use it as space to use as they see fit and fill it.
I end up having to constantly adjust for other people being morons and using the safe gap I’ve created to get that bit closer to a slip road etc.
Either that, or people tail gate me because there’s space in front and presumably they want me to fill it, even if it makes no difference to journey times…

Just stay on the first lane there is about a 200 minute gap because every muppet with less brain cells than wheels heads straight to the overtaking lanes because they’re the fast ones

I’m keeping two chevrons apart.

Especially when driving past Frodsham.

What I don’t get is the ones that follow for miles, but never overtake…
I had a car follow all the way today, at a couple of car lengths, from Pitlochry to Shloct(?) Summit, where they overtook at 70+ in the outer lane of slushy snow, having not edged past at any of the dual areas before…

It occurred to me if people roughly doubled the gap to be closer to what the Highway Code recommends, we’d effectively half the capacity of our roads at peak time.

On the other hand mind, a lot of the accidents and near misses and the traffic jams and congestion they cause would be avoided, so throughput would be greatly improved…

stay in the outside lane at 70 mph nobody can overtake you then legaly,works foir quite a few muppets who have progressed from the middle lane at 60 mph

The radar cruise on my V60 will maintain a 0.75 second gap, which is slightly-more-than-average distance for the M25. People just pull into it, and some drivers will actively undertake to fill it up if they judge that I’m not tailgating the car in front.

My feeling is that if Volvo think their car can safely maintain a 0.75 second gap in the dry, then who am I to argue? It’s jumped on the brakes fairly aggressively at times but hasn’t gone into the back of anything (yet).

Two seconds is an enormous gap on the motorway and I only drop back to it if there’s heavy rain.

IMO, leaving a gap is less about being able to stop (although at some point that IS useful) but much more about opening your vision up. I would say 99.9% of drivers i see day to day are completely re-active, rather than pro-active. As a result they tend to simply drive into bad situations that with more visibility and observations are blatantly obviously unfolding!!

I am obsessive about a decent gap which causes all sorts of rows with passengers. There is no excessive. Fill that gap and you are a complete s+++. If some one does I back off. If I am tail gated I cap the brakes left footed until the s*** behind backs off. I like to think that they think I am trying a bit of a deliberate accident. There is no bloody excuse and failure to maintain that gap whatever the situation makes you a antisocial selfish smart arsed t***

Fatal on M6 southbound between jct 39 & 38 Shap and Tebay.

I don’t know the details but yes that was probably the one. 🙁

My car has a pop-up display that shows the time gap between me and the car in front. Clearly that demands research

😀 That’s quite cool – I was actually thinking it would be an interesting geeky experiment to hook up a little rangefinder to a raspberry pi or something and log what the average distances were. Didn’t realise that some cars had that already.

Your 0.65 second figure fits with what I see. Anything more than roughly 20 meters at 70mph is fair game, regardless of conditions.

Out of interest does your car give any kind of alarm on that display if the gap is too small?

My feeling is that if Volvo think their car can safely maintain a 0.75 second gap in the dry, then who am I to argue?

Interesting one that because I guess part of the reason for the two-second rule is to allow for reaction time, but if the car is doing your reacting for you then where does that leave us?

Mind you, presumably all the car can do is apply the brakes. It can’t take avoiding action (yet).

Seems likely that autonomous/driverless cars might eventually help with this.

Two seconds is an enormous gap on the motorway and I only drop back to it if there’s heavy rain.

And yet that would still be half the recommended distance in heavy rain. 😕

stay in the outside lane at 70 mph

What? Even if the other lanes are free?

🙄

IMO, leaving a gap is less about being able to stop (although at some point that IS useful) but much more about opening your vision up

Agreed, to an extent. You’re a lot safer if you’re looking through the car in front (and so on) which lots of drivers don’t seem to do at all, but still there are also situations that can arise pretty much totally unpredictably

Out of interest does your car give any kind of alarm on that display if the gap is too small?

Yeh – I can set it to my choice of gap, too. All it does is flash but that’s fairly effective

I always leave at least 2 seconds. I count down the gap whenever I find myself too close. Just something I always do as routine.

On dual carriageways and motorways I think it’s actually more important. Traffic stopping in front can be less predictable, and peoples reaction times lazier. Passed a pile up the other day in the outside lane, nowhere near any junction. Just people being idiots. There’s no reason for it.

Not only that, and this is something that really angers me. Traffic flows better if you leave a gap. Especially on motorways and dual carriageways. When everyone’s bumper to bumper, no one can get off the slip road without someone slowing down and letting them in….which they usually do at last minute after accelerating up to the car in front, meaning they have to brake harder! Then you have the cascading brake effect. Then you have me sitting at the back, travelling at 5 friggin’ mile per hour. I genuinely have a hard time getting my head around the idea that people think they’re getting to work quicker by driving like this, whilst every morning consistently achieving the opposite. Do I have this wrong?

Even if you take all this out, it’s inconsiderate, and aggressive. Cars really bring out the worst in people. You can probably tell it’s one of my bugbears.

Oh, and this…

IMO, leaving a gap is less about being able to stop (although at some point that IS useful) but much more about opening your vision up.

The amount of people I see driving a few feet behind vans and trucks who can clearly see nothing that is coming up. Especially bad for any cyclists who might be just up the road.

Yeh – I can set it to my choice of gap, too.

Interesting. I wonder how long it will be before insurance companies get in on this and those “black boxes” start recording speed and stopping distances?

Could be quite conclusive in a disputed case.

Out of interest does your car give any kind of alarm on that display if the gap is too small?

Yeah, on the Volvo you get an orange warning bar projected onto the windscreen if you get too close when driving normally. It actually triggers at a greater distance than if the cruise control is on, so I suspect it’s as you said and it’s taking reaction time into account.

Radar cruise is solely reactive, though, and many times you can see what’s happening half a mile or more down the road and begin to increase the gap or slow down gently before the car in front is even aware.

I think many people are focussed on the 10 feet of road in front of their car as you’ll often see people almost go into the back of the car in front just by catching up on it, and it’s not surprising that we have major pileups on the motorway.

First thing my dad taught me when driving on the motorway was to look as far ahead as you possibly can.

matt_outandabout – Member
What I don’t get is the ones that follow for miles, but never overtake…
I had a car follow all the way today, at a couple of car lengths, from Pitlochry to Shloct(?) Summit, where they overtook at 70+ in the outer lane of slushy snow, having not edged past at any of the dual areas before…

I must have been the next car back because I saw that happen at the Slochd this afternoon on my way back from Dundee. You were doing about 60, which seemed fast enough for the conditions.

It looked to me like he moved out to overtake and only then thought “Oh shit” because he took forever to complete the overtake probably after realising what the surface was like.

It looked dodgy, I slowed down a bit to leave room for the accident. 🙂

Being a BMW driver I apply the same principles as when riding my track bike at the velodrome – close the gap, get tucked right in there and save fuel 🙂 I can often get the computer up to 47mph and save even more by not wasting electricity with the indicators….

Scaredypants I concur (sadly I use that road everyday). The other phenomenon I have noticed is the gap shutters who are not limited to that road.

Outside lane variety. These ones leave a decent gap right up to the point an inferior car indicates to pull out and then you see the puff of exhaust dust and the car squat under power and they’re in the boot of the car in front. If the exiting car by some miracle gets safely into the space before the shutter closes the gap too far they are usually rewarded by flashing, honking and the sight of a vein in the shutters forehead exploding in their rear view mirror. Regular culprits are vans, 4×4 and any vehicle the driver sees as making them superior.

Middle lane variety are as above and/or just generally hurtling towards whatever car is in front fixated on its tail lights, never looking left or right. At 20 yards to go the brakes get smacked on hard to a following distance of exactly 0.27 car lengths. Watch out could be anyone.

Inside lane variety follow at a safe distance until the inside lane crosses an entry slip then hammer it into the path of any car joining the motorway.

i always leave at least a 2 second gap, it makes for smoother progress, (something my passengers regularly comment on)
obviously, i can only control the gap in front of me, the gap behind is entirely dependent on the driver following me, however, there are 2 points to consider;
1:if you drive into my bus, there is every chance that i wont feel a thing.
2:if you drive into my bus, it will take a fair bit of explaining, due to it being 12′ high and 8′ 6″ wide and being painted yellow.
similar to a poster above, im not claiming driving god status either.
i am also aware that the majority of drivers, including many of my colleagues, do not think it matters that much.

IMO, leaving a gap is less about being able to stop (although at some point that IS useful) but much more about opening your vision up. I would say 99.9% of drivers i see day to day are completely re-active, rather than pro-active. As a result they tend to simply drive into bad situations that with more visibility and observations are blatantly obviously unfolding!!

This plus 1.

In a similar vein you can’t pull a single carriageway overtake nearly as safely or easily from 6ft behind the other vehicle. Drop back 50 feet and it makes an incredible difference to how far you can see and how much easier it is.

Being a BMW driver I apply the same principles as when riding my track bike at the velodrome – close the gap, get tucked right in there and save fuel I can often get the computer up to 47mph and save even more by not wasting electricity with the indicators….

Can’t wait until I can afford a BMW and be able to reach the dizzy heights of 47mph 🙂

Good thread. I do try (count one elephant, two elephant) but not always ideal. I do drive like a grandad these days though.

Hand’t *really* though of the vision thing before except in reverse – always amazed at the folk that make overtakes on lorries from 5′ off their tailgate 🙁

I’ve driven up and down the A9, off and on, for ? 35 years, seen the aftermath of at least two fatals in that time, both times I would have been only minutes behind the incidents so do have a frisson of the dangers..

50 zone on the M5 southbound from 4A past five is interesting, gaps start off reasonable but by the time I get off at five we’re driving in each other’s pockets.

What ever happened to that new tailgating offence that they made a big deal about a few years ago?

Has anyone ever actually been convicted of it?

I guess it is a little harder to prove than speeding.

I can often get the computer up to 47mph mpg

But you knew that 🙂

If you leave a 2 second gap on the M6, 3 cars and an artic will go into it. It’s kind of maddening that it’s often basically impossible to do what should be absolutely basic safety stuff.