Overtaking technique

BrianD3 · 23-07-2006 12:51PM

Hobbes wrote:

TBH I can't see how being less then the safe braking distance behind the car prior to overtaking being anything except reckless.

It's about minimising risk though not eliminating it completely. It could also be said that moving onto the wrong side of the road when you're still a safe braking distance from the target and only then accelerating can be reckless.

I can understand closing up a 10+ car gap but not coming closer then safe braking distance.

But 10+ car lengths may be the safe braking distance. Eg at 80 km/h you're covering 22 metres per second. If you go by the 2 second rule then you should be leaving a gap of at least 44 metres to the car in front at this speed. If an average car is around 4 metres then that's 11 car lengths. Add a damp road into the equation and you should be leaving more of a gap. Add the fact that you may be acclerating towards the back of the target before overtaking rather than travelling at a steady speed and the 2 second rule goes out the window

ninty9er · 23-07-2006 02:06PM

Most/All 80 kph roads are unsuitable for overtaking/80kph limits meaning you are at somestage going to get stuck be hind a slow moving vehicle (Mainly 80's Pajeros with 80 yr old men at the wheel or a tractor) having no choice but to stay behind it.

The VRT effect also causes it to be unsafe for many people to overtake since the power/weight ratio in Ireland is quite low as people buy the smallest engine possible in any given vehicle unless they've just won the lotto

I drive a 1l and would rarely/seldom overtake on anything other than a
DCway or Motorway unless the vehicle in front was very slow moving on a Single Cway N route.

I would have to be able to see for over a mile before my car would gather the speed required to overtake someone doing 70/80 in a 100 zone.

Bringing me to: if you can't floor it due to lack of power; is it best to drop back behind the car in front then gather speed and overtake????

Just looking for more experienced opinions

peasant · 23-07-2006 02:57PM

Bringing me to: if you can't floor it due to lack of power; is it best to drop back behind the car in front then gather speed and overtake????

If you know your car can't hack it, it's best to just stay behind, keep a safe distance and relax (and watch your mirrors, as a faster car from behind might want to overtake you, which you should allow by leaving a gap and keeping left)

If you have to let yourself fall back to spool up enough speed to even think about overtaking, that means that your car will still only be marginally faster than the "target" once you get to do so. It further means that you will have to spend ages on the wrong side of the road ...which is very unsafe.

So just stay behind without blocking other cars that could overtake.

Big Balls · 23-07-2006 03:14PM

To me, it's people like 1.4 Golf man overtaking in 5th that are causing a lot of these road deaths. Not enough power and not enough brain cells.

I might not need to take the car out of 6th to overtake a lot of the time which means I'd be in the 'move into the opposite side of the road and put the boot down til you're on the other side again' category too. If I want to overtake a few cars at a time, I'll select 4th.

All these "emergency plans" people mention are pretty crazy. Let's say you're driving along a national route in Ireland and you're overtaking and something or other goes wrong, there's very little you can do about it other than brake hard. You're talking seconds here lads, most of the drivers in Ireland are not fighter pilots, they're driving underpowered cars that wouldn't pull your granny out of bed... some of you are expecting wayyyyyyyyy too much from your fellow road users. :rolleyes:

Hotblack Desiato · 23-07-2006 11:37PM

I drive two 1 litre vehicles - a Triumph motorcycle and a Corsa - the overtaking performance is rather different

On the bike, overtaking is a breeze. The major frustration is continuous white lines set for an asthmatic Ford Anglia :rolleyes: in other words, where there is more than adequate view ahead for a vehicle of good performace to perform an overtake safely. But on the other hand, I'm never tempted to take an even slightly dodgy overtake, as I know it won't be long before a legal and safe opportunity presents itself.

In the Corsa, it's more of a challenge in that you need to be ready to go as soon as the opportunity arises. Maintaining a sensible (but less than the standard following distance) gives you the opportunity to change down to 4th and gain a bit of speed before having to pull out. Making the maximum, within the law and within the bounds of safety, of the performance of one's vehicle is very satisfying, and the 1.0 Corsa can live happily on the outer lane of the motorway - accelerate, pass, pull in. I hold no-one up but few pass me, oddly enough!

It's amazing how many of the "tailgating, flashing lights, get-out-of-my-way-pleb" crowd are actually very poor drivers who, between their bursts of rapidity, lapse into a daze. Rarely on a long trip do they finish more than a few car lengths in front of the 1.0, 65+mpg Corsa. Guess the joke's on them eh

mloc123 · 23-07-2006 11:44PM

ninja900 wrote:

65+mpg Corsa

eh where are you buying your petrol? must be great stuff...

unkel · 24-07-2006 12:30AM

cargrouch wrote:

When I started driving I was told "treat everyone else on the road as if they are mentally deficient or unstable"

Sound advice. Always suspect your fellow road user to do the worst

mike65 wrote:

Hence the need for two+one roads where multi-lane highways can't be justified.

I'll second that. Provided the central dividing barrier is of the proper steel type and not the bikah-slicah that won't stop a heavy vehicle from crossing over either

green-blood · 24-07-2006 12:45AM

we're pretty much dealing with single carriageway here, one lane each direction, mostly Irish trunk roads with 80 or 100Km limits yeah, ok, good.

no mention of road markings or signage before overtaking I notice

the road markings are there for a reason, especially the solid white lines, pay attention to them, no matter how well you "know" the road. I am truely sick of hearing that from people.

secondly, lets use an example I know mesnelf, we regularly do a run to Carlow from Dublin thru' Blessington and Baltinglas (n80/81) to visit friends, I'm starting to know the road and know where the best stretches to safely overtake are so similar to the "2 and 1 system" I dont get worried if I'm stuck I know when and where the opportunity will arise, hopefully. Anyway, there is one particular stretch that is nice and clear and you can see the road ahead, but it is NOT safe to overtake, which I know because some twit usually takes me there even at or slightly above the limit, and if I see them coming I make damn sure I leave them a gap, often I slow down so they get back on the right side of the road ASAP - why, because of the nice, well positioned, with loads of time road sign indicating a T junction approaching, a blind one at that, to our right joining the main road, where cars turning left, ie towards us, tend to look right (never left) and GO - twice I've seen near misses as Mr overtaker nearly "head-ons" Mr turning left......

of course while you're in the "tail gaiting position" thats being promoted here, your looking right past the "target" car, as best you can becasue you are now obviously too close really to see properly, and not at the road signs, on your left, are you?

Thats one reason why the IAM (an others) teach the method they teach.

green-blood · 24-07-2006 12:47AM

my God, 4th in 1 litre corsa is not an overtaking gear.... your on a bike as well man, surely you know about the revs/tourque/power equatiosn.

Hotblack Desiato · 24-07-2006 01:25AM

mloc123 wrote:

eh where are you buying your petrol? must be great stuff...

Same place you are mate. It's called efficiency.

green-blood wrote:

my God, 4th in 1 litre corsa is not an overtaking gear.... your on a bike as well man, surely you know about the revs/tourque/power equation.

Whether it's an overtaking gear or not depends entirely on what speed you're doing.
Changing down to 3rd isn't really appropriate above 30-mph.
So what's your point?

green-blood · 24-07-2006 04:41AM

Point is - we're talking about overtaking, safely, so we for the most part are dealing with trunk roads with a "target" vehicle to overtake travelling at or a small amount below the legal limit, lets say 65/70 in an 80, or 90 in a 100.

For both of those cases, in most manual cars, admittedly not all, but especially in a 1ltr Corsa as was the example, 3rd is the ideal gear to overtake from those starting road speeds, 4th is top, 5th dear boy is still (in a 5 ratio gear box) usually an overdrive. Even a 1ltr Corsa has a useful rev limit of 6000rpm, with peak power produced very close to this upper limit, above 30mph in 3rd the engine will only be running at half its peak rev limit and wont be approaching peak power.

I'm not slagging, with use of 3rd it'll be past significantly safer than 4th.

oh, no 1ltr corsa does 65mpg (even the asthmatic 3 cylinder) unless you're deliberately on a very strict ecomony run, in which case it certainly is not compatible with overtaking in an effort to make progress.

quote - honest john website
The £8,495 Club 1.0 12v 5-door offers 50.4mpg in the combines cycle

Big Balls · 24-07-2006 10:00AM

GB - on your point about the drive to Carlow - as far as I know, it's illegal to overtake when passing a junction so the mentally challenged you talk about shouldn't be doing it in the first place.

MercMad · 24-07-2006 11:26AM

GB - on your point about the drive to Carlow - as far as I know, it's illegal to overtake when passing a junction so the mentally challenged you talk about shouldn't be doing it in the first place.

..........yeah but GB is right about the vehicles position, you cannot see signs from a "tailgating" position, and you certainly wont see whatever it is that the car in front might try to avoid.

For certain a lot of overtaking is done whilst approaching junctions that have not been seen.

And BTW I regulalry drive a 1.0 ltr Corsa, it will overtake very well in 4th at those speeds and I sure get over 60MPG !!! It a 3 cylinder, it takes no time to spin up to max RPMS !!

SonOfPerdition · 24-07-2006 01:08PM

nereid wrote:

As far as I am aware, none of the Advanced Driving courses take into account the power/torque of the vehicle because the concepts apply generically across all vehicles.

This is referred to as "acceleration sense". Adequate knowledge of your vehicles acceleration and deceleration (via compression braking ) is an essential tool in good overtaking. This was emphasised to me in my Rospa training, and it's mentioned in "roadcraft".

green-blood · 24-07-2006 01:28PM

I'll defer to to better knowledge of those driving 3 cylinder 1 ltr corsas regularly, have driven one I wouldn't like to be putting my fate in it to get me past safely in 4th on an overtake

mloc123 · 24-07-2006 02:06PM

I can't believe people going on about how well a 1litre Corsa can overtake in 4th gear. Drive a well powered car and you will realise how slow it is.

Idleater · 24-07-2006 02:31PM

SonOfPerdition wrote:

This is referred to as "acceleration sense". Adequate knowledge of your vehicles acceleration and deceleration (via compression braking ) is an essential tool in good overtaking. This was emphasised to me in my Rospa training, and it's mentioned in "roadcraft".

Yes, I agree, but the in the context in which I was replying, the power/torque of a vehicle is independant to the method of the overtake. It should be taken into account, but there are general principles that apply to the manouvre.

I specified that without considering power/torque, observation and reaction were key to the overtake.
Then I specified that having taken account of the situation, planned the manouvre, then the power/torque of the vehicle that you are driving can be taken into account to perform the manouvre quicker.

Similarly, when I was doing the RoSPA, I was taught to seperate out the vehicle that I was driving at that moment in time to the priciples that apply to the manouvre that I was undertaking, then adapt the manouvre to take into account the vehicle, then perform the manouvre.

For example a garda who might switch from a Deuville 650 to a Pan European within the same journey.
The overtake is easier on the pan, but the position, observation et al still needs to be done before the overtake is commenced.

Another example is for example, say getting onto an R1 from a AX100. The power/torque are completely different yet you should still apply the same observation/positioning/reaction to your driving.

The difference between different vehicles in power/torque as many other posters have pointed out determine how "valid" an overtake you are planning on doing is. An overtake of a tractor on an AX100 is probably equivalent to planning an overtake of a porche on an R1. But (on an open road) planning an overtake of a porche on an AX100 is generally ruled out

.

L.

MercMad · 24-07-2006 03:07PM

I'll defer to to better knowledge of those driving 3 cylinder 1 ltr corsas regularly, have driven one I wouldn't like to be putting my fate in it to get me past safely in 4th on an overtake

...............ever driven a 1.6 8valve Vectra ??

I can't believe people going on about how well a 1litre Corsa can overtake in 4th gear. Drive a well powered car and you will realise how slow it is.

.............what makes you think I havent/dont drive a high powered car ??

mloc123 · 24-07-2006 03:44PM

The fact that you think a 1 litre corsa is fast is a good give away.

green-blood · 24-07-2006 04:33PM

stop making assumptions ... you're doing a good job of the ass making.... trust me.

you should try a 1.3 skoda favorit....

mike65 · 24-07-2006 04:40PM

Children children children, powaaaaaar is not the issue, overtaking speed is. The two are not always related.

What you need when getting from 50-70 in a dash is known as "Oooomph"! The correct gear and the correct use of torque (if a manual) is what gets you past quickly that and hanging back enough to see when its clear and you can be in the right gear at the right moment to GO!

Mike.

mloc123 · 24-07-2006 04:45PM

mike65 wrote:

Children children children, powaaaaaar is not the issue, overtaking speed is. The two are not always related.

What you need when getting from 50-70 in a dash is known as "Oooomph"! The correct gear and the correct use of torque (if a manual) is what gets you past quickly that and hanging back enough to see when its clear and you can be in the right gear at the right moment to GO!

Mike.

True enough but while I am "ass making" I might aswell say a 1litre Corsa has no "Oooomph"

ianobrien · 24-07-2006 04:58PM

Question, do people know at what revs is the max power and torque produced for their car. I would thought that, for overtaking, having the engine at just below max torque would give you the ability to gain the speed needed for overtaking as quickly as possible. Then, as the revs climb, you move into the max power bracket, helping to maintain the overtaking speed. That is the way that I drive anyway.

I break the limit when overtaking, as I was taught to be in the wrong side of the road for as short as possible

When overtaking in a 1.0l Micra, I use third gear from 70kph to 125 kph (then just about to hit the rev limiter). In a 1.8 Primera, I use fourth gear for the same speed, as the torque is produced lower down the rev range.

In my opinion, there is never a hard and fast rule, as every situation is differert, and every car is different

green-blood · 24-07-2006 05:34PM

True enough but while I am "ass making" :eek:

ninty9er · 24-07-2006 08:43PM

mloc123 wrote:

True enough but while I am "ass making" I might aswell say a 1litre Corsa has no "Oooomph"

Not true. It just doesn't have ooomph above 50 mph. Best place for oooomph is exactly 32 mph in 2nd gear when you can actually feel the car move significantly.

Max pulling power is about 3250-3500 rpm. It drops a bit again after that which makes no sense to me.
I'm not in the habit of letting the rev counter go above 4500 as the noise from the engine isn't pleasant or safe sounding.

mloc123 wrote:

I can't believe people going on about how well a 1litre Corsa can overtake in 4th gear. Drive a well powered car and you will realise how slow it is.

In a 100 zone overtaking someone in a 2.5l Omega yesterday doing 85. I overtook in 4th simply because the oncoming traffic was a dot on the horizon. At those speeds I am usually in 5th and dropping back to 4th to overtake seems sensible to me. If there's any sign of oncoming traffic there's no point because the car is slow!!!!!!!! but insurance companies don't like the sound of 19 and 1.4

unkel · 25-07-2006 12:06AM

ianobrien wrote:

In my opinion, there is never a hard and fast rule, as every situation is differert, and every car is different

I can't see anyone disagreeing with that

I have never driven a 1 liter 3 pot Corsa, but at 70-80 km/h my gut feeling would tell me there is more torque available in 3rd than in 4th gear. I could be wrong of course

ninja900 wrote:

On the bike, overtaking is a breeze. The major frustration is continuous white lines set for an asthmatic Ford Anglia

Interesting point. Never thought of that from a bikers point of view but you are right. I always thought those continuous lines were designed for slow cars which has slightly annoyed me in the past. I now appreciate a bikers' frustration about that a lot more. Acceleration on a slow bike is quicker than acceleration on a fast car and all that

Gerry · 25-07-2006 10:49AM

This thread unfortunately confirms a lot of my suspicions about Irish drivers. A lot of posters on this thread don't understand the importance of accelerating quickly past the car when overtaking. Sometimes, you will not need to accelerate much, lets say if you can see the road is clear while you first approach the car in front, you can just drive past in whatever gear.
But, a lot of the time, you need to shoot past the car in front. It seems that people would rather that the engine sounded quiet, than complete an overtaking manouever properly.
Yep, with a small normally aspirated petrol engine, you are going to have to rev it. If you are worried about revving it over 4500rpm, maybe you should have taken it for that service. A car in good condition will not be harmed by revving it to where the red zone starts on the rev counter.
My first car was a nissan sunny, now it wasn't exactly slow, as it was a 1.4, 16 valve, and is fairly light. But, you wouldn't know this unless you revved the crap out of it. Currently I drive a saab 900 turbo ( manual ). It makes overtaking really safe, as it has loads of torque from 2000 rpm upwards. I haven't needed to use the brakes trick, I just accelerate a little before pulling out, and keep a few car lengths behind the car in front.
I suppose the fact that most Irish people value the reg plate above all else helps to explain why there are so many newish 1.0-1.2 cars on the road, trying to overtake people at 40mph in 4th or 5th gear. If you don't know how to use the gears properly, you shouldn't be on the road.

Idleater · 25-07-2006 12:27PM

Gerry wrote:

This thread unfortunately confirms a lot of my suspicions about Irish drivers. ...
But, a lot of the time, you need to shoot past the car in front. It seems that people would rather that the engine sounded quiet, than complete an overtaking manouever properly.

The flip side to this is of course, if you have to "shoot past" then perhaps the conditions are not sufficiently safe for you to complete the manouvre safely.

Safe progress for the "overtaker", "overtakee" and other road users was actually the main premis of this thread.

L.

Gerry · 25-07-2006 02:35PM

In the common situation, where there is oncoming traffic some way off, the rate at which you overtake ( plus an initial delay ) is the difference between a near miss, a slightly dodgy manouever, or a perfectly safe manouever.

Hobbes · 25-07-2006 03:06PM

BrianD3 wrote:

But 10+ car lengths may be the safe braking distance

If thats the safe braking distance (SBD) you shouldn't be overtaking to begin with.

Fact is you come in below SBD and I slam on my brakes while your about to turn, your turning angle is going to have to be really sharp faster or you risk ramming the car. Slamming on the brakes at that point means your liable to hit, and if you already moving out and hitting the brakes you will have less control in the turning.

Overtaking technique

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