Domino effect and Tailgating

BrianD3

On Tuesday I was in a slowish moving line of traffic on the N4 near Enfield. There were at least 50 cars in the line which was moving at a speed varying from 35 - 50 mph. There was no chance for anyone to overtake due to constant oncoming traffic. In any case, the stretch has no overtaking signs and a double continuous white line.

I sat back around 6 seconds from the nearest car in front and had a great view right up along the queue ahead as they tailgated, braked, accelerated etc. The domino effect as the brake lights came on was very obvious. In a few miles I'd say each car had braked 40-50 times whereas I had braked zero times due to leaving ample space to adjust my speed using throttle only. My trip computer told me I was doing 52 mpg (not bad for a 1.6 litre petrol family car)

Saw a truck a few cars back employing a similar strategy.

It is such a simple thing but I reckon if everyone did this:
a) Traffic would flow better. More road space would be used if vehicles left bigger gaps however I think this would be negated by the reduction in domino effect.

b) Oncoming right turning vehicles would have a chance to cross the road due to good gaps in the traffic. This would improve traffic flow and make rear ending crashes less likely.

c) Everyone's brake pads would last longer and engines would use less fuel. Result: more money in everyone's pocket and better for the environment.

d) If someone did wish to overtake, they would be able to slot into the gaps between cars instead of having to take 10+ cars in one manerouvre due to drivers not leaving enough space in front of them for an overtaking car to move into.

e) drivers would get less stressed and tired.

Anyone have any comments on this. Are there any disadvantages to leaving a big gap like this. Do drivers behind start to get stressed if they see someone ahead of them "wasting space".

BrianD3

Eoin

I had braked zero times due to leaving ample space to adjust my speed using throttle only

My only problem would be that the driver behind you has not been given a clear indication that you have stopped, as your brake lights have not flashed at all.

ambro25

BrianD3 wrote:

Anyone have any comments on this. Are there any disadvantages to leaving a big gap like this. Do drivers behind start to get stressed if they see someone ahead of them "wasting space".

No disadvantage whatsoever. When traffic bunches up, I usually dive straight into the lorry lane ASAP, as there guys are clued up about exactly what you're saying, and in the blink of an eye I've usually gained 500 yards on everybody squeezed in the overtaking lane.

Don't mind 'big gaps' ahead, so long as the guy moves well (e.g. not doing 10 mph either, another extreme of the scale).

Only 2 real problems I see with this approach are:
every other bunched-up guy on the right jumping in the space
some bunched-up guy on the right jumping into of you as they don't check their blindspots / don't care & think you're wrong to overtake on left

ambro25

eoin_s wrote:

My only problem would be that the driver behind you has not been given a clear indication that you have stopped, as your brake lights have not flashed at all.

Sorry, eoin, but disagree: whatever happened to due care & attention?

fletch

Every day I try to employ this tactic on the M50 by staying in the inside lane & leavin a nice big gap in front of me. It's great cause you watch the cars in front accelerating sharply then having to break sharply, meanwhile I potter along at a nice steady consistent space.....sometimes gets annoying in heavy traffic when fellas on the outside lane keep diving in, in front of ya though

fletch

ambro25 wrote:

Sorry, eoin, but disagree: whatever happened to due care & attention?

And you won't be decelerating sharply so the driver behind should have more than enough time to react to your reduction in speed

Green_Martian

I have to agree with BrianD3 i usually employ this tactic when stuck in traffic, not only on motorways but also the busy Oscar Traynor road in Coolock.

I personally feel more relaxed when i leave a gap between me and the car in front, as you have plenty of time to see them break or slow down, rather than driving up their ar*e when if they jam on your in their with them. Plus as stated you are saving your breaks

Eoin

Sorry, eoin, but disagree: whatever happened to due care & attention?

I don't think that people do give enough due care & attention, hence my point.

edmund_f

found a simple solution to this.. and am so going to incur the wrath of people on here..

_Dont_live_in_Dublin_

but do totally agree with the 'driving in the slow lane' comment, usually much quicker as everyone assumes that the right hand lane is faster, plus you do not have some ( ) driving on your bumper?

BrianD3

eoin_s wrote:

I don't think that people do give enough due care & attention, hence my point.

True, but surely you are making life *easier* for the muppet behind by slowing gradually using the throttle than slowing more suddenly using the brakes. If I'm being tailgated I always leave a bigger gap between myself and the car in front of me. In effect I am making a braking space which is not only big enough for me to stop safely, but big enough for me to stop safely and very gently.

As for brake pads: I have 67k miles on my front ones and they're still 7-8 mm thick. I predict I'll get another 15-20k miles out of them before they're down to the minimum thickness which is 3.5 mm. They will be replaced then, unlike a lot of Irish motorists I won't leave them until the calipers start scraping on the discs

BrianD3

ambro25

eoin_s wrote:

I don't think that people do give enough due care & attention, hence my point.

Then we're in agreement. But possibly I don't see this as as much of a problem in the situation depicted herein - it is true of any place you drive, around these parts, especially in town.

BrianD3

Gkelly2002 wrote:

I have to agree with BrianD3 i usually employ this tactic when stuck in traffic, not only on motorways but also the busy Oscar Traynor road in Coolock.

I personally feel more relaxed when i leave a gap between me and the car in front, as you have plenty of time to see them break or slow down, rather than driving up their ar*e when if they jam on your in their with them. Plus as stated you are saving your breaks

Yeah, and you're also saving your clutch. People who drive right up the arse of the car in front in traffic end up spending more time slipping the clutch - they have to as if they engage it fully they would hit the car in front. If you hang back a bit you can engage the clutch fully immediately after you start moving and then let the car chug along at low revs. Works very well if you have a diesel engine and/or a newish car with good engine mounts.

BrianD3

delly

Clever driving = less stress.

I always employ the tactic of leaving a gap in front of me, and i spend as little time as possible in the overtaking lane, even if i'm running at top speed (120 km/h ). I remember seeing some crazy statistic in England, that 30% - 40% of the motorways are unused because people stick to the outside lanes.

Also, i try to keep the car rolling when approaching a red light, with the net result that i don't have to stop before the lights turn green.

impr0v

I remember seeing some research in a professional journal from the Transport Research Lab in the UK about the domino effect you refer to and, while I can't remember the exact details, they had established that somebody pressing their brakes un-necessarily in heavy traffic conditions can have an effect up to ten miles back on a motorway. Time might have exaggerated the effect, but you get the idea.

loyatemu

in england (and maybe elsewhere) they have variable speed limits on the motorways to avoid this kind of domino effect which causes "phantom" traffic jams - ie: one guy brakes, the cars behind him brake, eventually cars further back have to stop, traffic starts bunching up and tailbacks of several miles can be caused. When traffic is heavy the speed limit is

Dan_B

The other side to this is if I leave enough of a gap to fit a Fiat 126 some idiot will try and put a cement mixer into it and take half my bonnet with them!!

Green_Martian

BrianD3 wrote:

Yeah, and you're also saving your clutch. People who drive right up the arse of the car in front in traffic end up spending more time slipping the clutch - they have to as if they engage it fully they would hit the car in front. If you hang back a bit you can engage the clutch fully immediately after you start moving and then let the car chug along at low revs. Works very well if you have a diesel engine and/or a newish car with good engine mounts.

BrianD3

This is also another factor, wearing the clutch out in a traffic jam....where are you going nowhere so whats the point in driving up someones ar*e. You will end up forking out more money on Brakes and Clutche sthis way...plus if you then hit someone you looking at handing over a loada wad aswell.

I have my car since new(its a 02) and i have only done about 17500 on it but the brakes are still great. My uncle usually checks every month or so just to make sure they are ok, cos i get a bit nervy that they have never been changed, but he says they are grand as i dont drive hard on the brakes like others do

AMurphy

BrianD3 wrote:

On Tuesday I was in a slowish moving line of traffic on the N4 near Enfield. There were at least 50 cars in the line which was moving at a speed varying from 35 - 50 mph. There was no chance for anyone to overtake due to constant oncoming traffic. In any case, the stretch has no overtaking signs and a double continuous white line.

I sat back around 6 seconds from the nearest car in front and had a great view right up along the queue ahead as they tailgated, braked, accelerated etc. The domino effect as the brake lights came on was very obvious. In a few miles I'd say each car had braked 40-50 times whereas I had braked zero times due to leaving ample space to adjust my speed using throttle only. My trip computer told me I was doing 52 mpg (not bad for a 1.6 litre petrol family car)

....

d) If someone did wish to overtake, they would be able to slot into the gaps between cars instead of having to take 10+ cars in one manerouvre due to drivers not leaving enough space in front of them for an overtaking car to move into.


BrianD3

Overall a good stratagy..... unfortunately it's ROI and IMHO you represent <10% of the driving public. The other 90% are seething that you are leaving a space and would just love to occupy it for you, not that it makes a hoot of difference, but that is the mentality.
I have in similar situations (close to Dub,) had someone jump ahead to the gap, and 10 miles later they are still there, so all that stress for 20 feet, great progress I think not.
I like the idea of passing in the climbing lane..... just demonstrates the lunacy.
We get that here too, someone hogs the fast lane for miles.... no hassle, just go inside and let them there.

As for braking, etc. with a sizeable gap, you need never brake as you indicated, just modulate the acc. foot.

re; My only problem would be that the driver behind you has not been given a clear indication that you have stopped, as your brake lights have not flashed at all. .
Who said anything about stopping?. The objective is keeping a very smooth progress pattern, independant of whatever is infront and behind.

An even better item to keep an eye on if possible. The car in front of the car in front of you. If it has a high mounted 3rd brake light. You will see this at the same time as the car immediately ahead, therefore you can expect the one ahead to light up about 0.5sec later... u can use that 0.5 sec to your advantage.

I've had to do the 10 car jump once, not to be recommended unless you drive a rocket. The leaders of more than 5 vehicle trains should be given tickets for holding up traffic, plain and simple.
What I have seen occur is, one 5 car train will catch up with an slightly slower 5 car train, ad infimatum, so the slowest vehicle is setting the pace for the trailing pack and as for pulling over... not till hell freezes over.

Silvera

I totally agree with your original post above, BrianD3 !!!

I've often wondered if I was the only person driving like you describe ...... but now I know there are at least two of us

stratos

Yes I do it too. I even try to see how far i can go without using my brakes. People do sometimes jump into the space, ah what the hell, let him wear his brakes and suspension out, whilst i save fuel. It also makes you look ahead and see what traffic is doing, maybe 10 cars ahead. A survey was done in the U.K. where driver had eyeball position detectors put in their cars. The survey found everyone of them did not look far ahead enough.

unkel

I'd go even further. I enjoy driving smoothly. A lot of the time instead of braking, I have my right foot over the brake when it looks like I might have to use it

So rather than braking anyway, I let the car coast and minimise my response time in case braking is required

Having said that, one of the main reasons I like driving a powerful car is that if I'm coming up to a 10 car slow train, I have a better chance of overtaking it quickly and safely. Obviously my top speed during this manoeuvre would be higher than the speed limit. I rate safe driving higher than driving within the legal speed limit.