Nearly had a wipeout undertaking today

Damien360

On M1 not far from border, white kangoo van on right lane doing 80kmph. Silver C4 up it's arse looking very impatient. I approached from way back on left lane and slowed to about 100kmph making the decision far back that I would undertake but not zoom by just in case.

Just as I got alongside the 2 cars during the undertake the C4 driver gave the kangoo a flash. The kangoo immediatly dived in to the left and I had to take the hard shoulder to avoid a big smash involving all 3 of us. Looked back in my to see why he never looked and he was on his phone.

Now I believe I would be 100% at fault for the undertake if there was a smash but would the driver of the kangoo be at fault for failing to look before changing lane, ignoring the fact he was on the phone which might be hard to prove ?

There was a case lately in leinster leader of a driver getting a big fine for undertaking on M7 and his excuse was the slow speed of the driver in right lane. It did'nt wash with Judge Zaiden at all.

CR 7

I wonder what way the law is with regards to this type of undertaking?
Staying in the left lane, at a reasonable speed, and passing cars that are sitting in the right lane. I would have thought undertaking requires switching lanes before and/or after passing a car?

In your case I would think the van driver would be partly at fault, not using adequate observation.

Atomic Pineapple

Would be 100% your fault for undertaking, its illegal exactly for this reason, a car moving from the overtaking lane into the driving lane wouldn't expect a car to be there as it shouldn't be

PCPhoto

in a court of law you would have to argue contributary negligence on the behalf of the Kangoo (ie. no look and on phone) .... which would more than likely have an opposition legal team bricking it (to be fair).

I need to backtrack a bit: if there had been an accident, blah blah blah... bike/personal injuries .... gardai decide no action to be taken by them (ie. allegations of motorist on phone !! Dangerous Driving - without due care and attention etc etc) - so matter becomes a civil claim between you and kangoo (I assume you and kangoo would have collided) .... other driver could be named as third party but would probably be released from proceedings.

(assuming that the matter went before a judge and didnt settle out of court ) on discovery your side would have claimed contrib negligence and gotten access to phone records of Mr Kangoo.... the legal team would be hard pressed to argue that he/she was paying 100% attention and a judge would have to find contributary negligence on the behalf of Mr Kangoo and in all likelyhood (depending on how good your legal team would argue) - the judge would probably find in your favour (but might reduce the award)

anyways - thats my view on the possible scenario..... you would be compensated in the event of an accident - but the award would not be excessively high - compensation for personal injuries, bike repair/replacement.

seamus

When changing lane you are obliged to yield to all traffic already in that lane. The Kangoo driver would be 100% at fault for failing to give way to you.

That you were undertaking is largely irrelevant.

robtri

Park Ji Sung wrote: »

I wonder what way the law is with regards to this type of undertaking?
Staying in the left lane, at a reasonable speed, and passing cars that are sitting in the right lane. I would have thought undertaking requires switching lanes before and/or after passing a car?

In your case I would think the van driver would be partly at fault, not using adequate observation.

you can only over take on left (except in slow moving queing traffic)

I spoke previouslt to eh RSA on this and asked what to do, should you continue on in the left lane driving under the limit and was told, under no circumstances would that ne acceptable.

move to the right lane and overtake or wait..... do not ever undertake.


so OP unfortunately you are 100% at fault

Danbo!

Phone or no phone, could the kangoo driver have seen you? If you're undertaking you're in their blindspot at some point, which cant be checked in a van as easily as a car

Voodoomelon

Surely if the OP was along side the Kangoo, then he wasn't undertaking?

As soon as he progressed further than the Kangoo, he would have been.

Anan1

This is exactly why I always use the horn when undertaking - I had a very similar experience myself on the M11 some years back.

galwaytt

Voodoomelon wrote: »

Surely if the OP was along side the Kangoo, then he wasn't undertaking?

As soon as he progressed further than the Kangoo, he would have been.

I'm sorry, but you're wrong.

Overtaking, and undertaking being the corollary, is the act of changing lane to get past a vehicle, and then re-emerging into that same lane again, ahead of the 'offending' slower vehicle.........in this case, the Kangoo....

If OP approached all the way along in l.h. lane, and his traffic lane speed is faster than that in the r.h. lane, and he continued past the Kangoo, and stayed in the l.h. lane, then, in accordance with ROTR, he did not undertake, and no offence was committed.

Read it for yourself, here: http://www.rotr.ie/rules-for-driving/good-driving-practice/overtaking.html

mike65

I would have moved across and "queued" silly as it sounds, the guy in front of me would then have felt he needed to make his presence felt and flashed, the lead vehicle would then hopefully get the fcuk out of the overtaking lane and let the vehicles behind go on their way.

angry_bob

That you were undertaking is largely irrelevant.[/QUOTE]

You really need to read the rules of the road. I've copied the passage from the RSA handbook.
Overtaking

Overtake only on the right, unless traffic is travelling in slow moving queues and the traffic queue on your right is travelling more slowly than you are. If you intend to move from a slower lane to a faster lane, adjust your speed first.


OP, you are 100% at fault for overtaking on the left, any accident would have been your fault.

Voodoomelon

galwaytt wrote: »

If OP approached all the way along in l.h. lane, and his traffic lane speed is faster than that in the r.h. lane, and he continued past the Kangoo, and stayed in the l.h. lane, then, in accordance with ROTR, he did not undertake, and no offence was committed.

I know what you're saying, but he did approach all the way in the left hand lane, and didn't continue past, he was level with the Kangoo during the incident.

Matt Simis

The OP would have handily stated that he was merely in the left lane, some moron didnt look in his mirror, make a sudden move and was on his phone. Case closed.
All this quoting of ROTR is pointless, court cases arent won on semantics and in this case, the idiot in the van was committing multiple infractions which nearly lead to an accident.

If the OP intended to overtake or not is irrelevant in the real world (put down your quotations), Joe Blogs pooting along in that lane may not have had the reactions of the OP (who was focused due to the very act of undertaking) and would have suffered a worse faith.

Anan1

galwaytt wrote: »

I'm sorry, but you're wrong.

Overtaking, and undertaking being the corollary, is the act of changing lane to get past a vehicle, and then re-emerging into that same lane again, ahead of the 'offending' slower vehicle.........

My understanding of 'undertaking' is overtaking on the left, simple as.

TherapyBoy

angry_bob wrote: »

Overtake only on the right, unless traffic is travelling in slow moving queues and the traffic queue on your right is travelling more slowly than you are. If you intend to move from a slower lane to a faster lane, adjust your speed first.

If I'm driving in the lefthand lane of a 3 lane motorway and I come across a car in the middle or outside overtaking lanes who is travelling at a slower speed than I am, should i cross 2 lanes to overtake & then return across 2 lanes to the inside lane or stay in the inside lane and undertake? Crossing multiple lanes could be seen as driving without due care & attention, staying where you are = undertaking. Either option isn't perfect, can anyone clarify which is the correct one?.

Voodoomelon

Matt Simis wrote: »

The OP would have handily stated that he was merely in the left lane, some moron didnt look in his mirror, make a sudden move and was on his phone.

That's what i'm saying. Who's to say he was going to progress further, even though we know he would now.

galwaytt

angry_bob wrote: »

That you were undertaking is largely irrelevant
You really need to read the rules of the road. I've copied the passage from the RSA handbook.
Overtaking

Overtake only on the right, unless traffic is travelling in slow moving queues and the traffic queue on your right is travelling more slowly than you are. If you intend to move from a slower lane to a faster lane, adjust your speed first.


OP, you are 100% at fault for overtaking on the left, any accident would have been your fault.

What nonsense - did you even read the ROTR, or the OP's post ? The only ass on the road, as MattSimis points out, was the Kangoo driver.

Anan1

galwaytt wrote: »

The only ass on the road, as MattSimis points out, was the Kangoo driver.

While agreeing completely that the Kangoo driver was an ass, every act of undertaking carries a risk of a similar outcome. This is why it's so important to use the horn, have an escape route, and be prepared for a potentially violent evasive maneouvre. Principles are for learners, the more I drive the more pragmatic I become.;)

unkel

Anan1 wrote: »

This is exactly why I always use the horn when undertaking - I had a very similar experience myself on the M11 some years back.

An overtaking lane hugger like in the OP is unlikely to move lane unless prompted. Prompting by horn is more successful than prompting by flash and / or tailgating.

Moral of the story: never undertake while the hugger is being tailgated. Don't use your horn either even if there is no tailgater

Anan1

unkel wrote: »

An overtaking lane hugger like in the OP is unlikely to move lane unless prompted. Prompting by horn is more successful than prompting by flash and / or tailgating.

Moral of the story: never undertake while the hugger is being tailgated. Don't use your horn either even if there is no tailgater

Unlikely, but it does happen. Using the horn when behind them is, as you say, dangerous - I use it when i'm coming alongside them, just to make quite sure that they know where I am.

unkel

Anan1 wrote: »

Using the horn when behind them is, as you say, dangerous - I use it when i'm coming alongside them, just to make quite sure that they know where I am.

For what purpose though? They might freak out and move into your path. Not using the horn doesn't disturb them and you are more likely to smoothly undertake and leave them (a hazard) behind.

Strongly agree with your point about escape routes though. I'm spending a lot of my driving time thinking about escape routes these days. Any time anything that comes on the "radar" that might have any risk and I switch primarily to avoidance and secondarily to escape options

Stainless_Steel

I always undertake with a lead foot and the roar from the stainless steeler...always make sure you have an escape route (well done OP).

Absurdum

galwaytt wrote: »

I'm sorry, but you're wrong.

Overtaking, and undertaking being the corollary, is the act of changing lane to get past a vehicle, and then re-emerging into that same lane again, ahead of the 'offending' slower vehicle.........in this case, the Kangoo....

If OP approached all the way along in l.h. lane, and his traffic lane speed is faster than that in the r.h. lane, and he continued past the Kangoo, and stayed in the l.h. lane, then, in accordance with ROTR, he did not undertake, and no offence was committed.

Read it for yourself, here: http://www.rotr.ie/rules-for-driving/good-driving-practice/overtaking.html

That would be my non-legal-knowledge-of-anything interpretation of the situation too. I see it every single day, particularly on 3 lane motorways/DCs because of middle lane hoggers.

Anan1 wrote: »

Unlikely, but it does happen. Using the horn when behind them is, as you say, dangerous - I use it when i'm coming alongside them, just to make quite sure that they know where I am.

Chances of Kangoo man actually hearing the horn are probably quite slim though.


Either way, if someone collides with another vehicle while changing lanes, they clearly were not paying attention - imo it doesn't matter if they were moving to the left or right.

Vertakill

I'd agree with a few other posters here in that I think, if it came down to insurance companies... I'd argue that the OP was parallel to the Kangoo when the Kangoo switched lanes.

Whatever way you look at it, undertaking gray area or no, the Kangoo has to ensure that the road is safe before switching lanes like that. That means going through the checking, signalling and moving spiel. If he'd done that, there'd be no issue.

If he wasn't hogging the 'fast lane' there would be no issue either.

I hope some of the people that don't think hogging the 'fast lane' is such a big problem see this so they can understand how needless accidents can happen by being a discourteous d1ck on the road.

bongi69

Bizarre-Ink wrote: »

If I'm driving in the lefthand lane of a 3 lane motorway and I come across a car in the middle or outside overtaking lanes who is travelling at a slower speed than I am, should i cross 2 lanes to overtake & then return across 2 lanes to the inside lane or stay in the inside lane and undertake? Crossing multiple lanes could be seen as driving without due care & attention, staying where you are = undertaking. Either option isn't perfect, can anyone clarify which is the correct one?.

You can cross multiple lanes on a motorway, provided you treat each lane change as a seperate manouver, and not just zoom across from lane 1 to 3. So you indicate, check and move out into the middle lane going straight. Repeat the manouver again and you're in the right lane.

langdang

Stainless_Steel wrote: »

I always undertake with a lead foot and the roar from the stainless steeler...always make sure you have an escape route (well done OP).

Yup, less time spent in the blind spot and general vicinity of another "passenger-in-the-driving-seat¨, and the small chance it might might jolt the gimp back from cloud-moron-land as you get yourself out of harm's way as quick as possible.

The rest of this has been done to death, let's just say that the only way the OP would have come out of an accident here scot free and smelling of roses is if he had just rezoned several flood plains, erected a load of shoddy houses, given loans to people who were clearly lying, and then bailed out shadey banks with our money and pimped us out to the IMF.
But if he had no NCT at the time he would have been going straight to hell. FACT.

seamus

Absurdum wrote: »

Either way, if someone collides with another vehicle while changing lanes, they clearly were not paying attention - imo it doesn't matter if they were moving to the left or right.

That's really the key here. When it comes to determining "blame" for an accident, you ask the question, "Who had right of way?".

It's usually only when the right of way is ambiguous that you look at other factors (such as speed, conditions, actions before the crash, etc).

In this case, the OP had right of way and the Kangoo field to yield. It's black and white.

Gophur

So, idiot or not, the opinion of most contributors is the traffic in the RH lane determines the maximum speed of traffic in all lanes?

If some driver drives at 50kph in the RH lane, then that is now the new maximum speed, as it is forbidden to pass on the Left?

You are allowed pass on the Left, if there is slow-moving traffic in the RH lane. (The definition of "slow" is vague, however.)

I have lost count of the number of times I have been meandering down the LH lane of the M1, with tens of cars all lined up in the RH lane, driving much slower than me. I am, and was, perfectly within my rights to continue at my speed, in my current lane. I am not supposed to

1 Join the clown in the RH lane,
or
2. Slow down to the same speed as the last clown in the RH lane queue.

At all times, each and every driver has an onus to be fully aware of all that;'s going on and to make all other drivers aware of his presence.

PeakOutput

seamus had the correct answer on the first page i dont know why
everyone just ignored him

it dosnt matter if the op was undertaking or not and it dosnt matter if he admits doing that or not

it also dosnt make a difference if the kangoo was on the phone

you are obliged to ensure the way is clear before changing lanes, end of discussion the kango would be held liable for 100% of damages by the insurance companies and if it went to court for some reason by the courts

IF the gardai saw you undertaking and wanted to prosecute you that would be entirely independant and would have no bearing on the outcome

plissken

galwaytt wrote: »

I'm sorry, but you're wrong.

Overtaking, and undertaking being the corollary, is the act of changing lane to get past a vehicle, and then re-emerging into that same lane again, ahead of the 'offending' slower vehicle.........in this case, the Kangoo....

If OP approached all the way along in l.h. lane, and his traffic lane speed is faster than that in the r.h. lane, and he continued past the Kangoo, and stayed in the l.h. lane, then, in accordance with ROTR, he did not undertake, and no offence was committed.

Read it for yourself, here: http://www.rotr.ie/rules-for-driving/good-driving-practice/overtaking.html

I'm sorry but it's you who is wrong, I think you need to more carefully
read the link you provided.

Specifically where its says:
You must not overtake when
You are in the left-hand lane of a dual carriageway or motorway when traffic is moving at normal speed.

Over the course of my day, it's not long before I lose count of the amount of numptys I have to undertake, as they sit in the overtaking lane with the same glossy look upon their faces that only the most inept seem to hold. Yet, I do so knowing full well that if an accident were to occur, it would be myself who would ultimately be held accountably. As flawed as it may be, in the eyes of the law it's "wrong" to undertake, and so anyone who chooses to do it, must do so knowing of the consequences if it doesn't go to plan.

Tipp Man

Anan1 wrote: »

This is exactly why I always use the horn when undertaking - I had a very similar experience myself on the M11 some years back.

Why undertake at all?? Why not move into overtaking lane and flash/horn the guy who is going slow

I really really hate undertaking, probably as much as people driving slow on the overtaking lane, but undertaking is probably more dangerous

Leonard Hofstadter

Don't the ROTR say that you can undertake is there is a slow moving vehicle/slow moving traffic in the right lane?

80 kph in a 120 kph road is very slow to me, nearly dangerously slow, I can't see anything wrong with what the OP did really, I know I'd do the same.

If the car hogging the overtaking lane was doing 100/110 kph then that's a different story and I certainly wouldn't go undertaking then, I would go behind the offending vehicle and indicate right(that usually gets people out of the way) but 120 kph is 50% faster than 80, and as such I can't see what is wrong with undertaking when there is that much of a speed differential, you can't but say the van doing 80 is a slow moving vehicle really.

Henry Ford III

"Slow moving traffic" seems to be an issue here. To me that means stop/start and certainly not normal cruising speed stuff.

I'd imagine the Gardai observed anyone in the driving lane cruising up at/near the speed limit and passing another vehicle in the overtaking lane they'd potentially have issues with both drivers.

plissken

Tipp Man wrote: »

Why undertake at all?? Why not move into overtaking lane and flash/horn the guy who is going slow
I really really hate undertaking, probably as much as people driving slow on the overtaking lane, but undertaking is probably more dangerous

And if said idiot remains oblivious to their surroundings what then, remain in the overtaking lane at a speed of the car in fronts choosing? Bollox to that.

Gophur

The Rules of the Road are not the same as the Law of the Land.

It is legal to pass on the Left, but that's not to say a fine member of our constabulary would attempt to prosecute you on the basis of Careless driving (or similar), where you will be up before some old fogie of a Judge who knows SFA about driving.

Tipp Man

plissken wrote: »

And if said idiot remains oblivious to their surroundings what then, remain in the overtaking lane at a speed of the car in fronts choosing? Bollox to that.

With that kind of attitude your worse than the slow guys in the overtaking lane and sum up in a nutshell why Irish drivers have no clue how to drive on a motorway

I do most of my driving on motorway and if you keep flashing they pull over, its pretty simple and a lot less dangerous

Gophur

PeakOutput wrote: »

............
you are obliged to ensure the way is clear before changing lanes, end of discussion the kango would be held liable for 100% of damages by the insurance companies and if it went to court for some reason by the courts

IF the gardai saw you undertaking and wanted to prosecute you that would be entirely independant and would have no bearing on the outcome

I admire your innocence. Don't you know , in such an event, the Insurance companies would nail both parties. Better to have two parties lose their NCB, than one! :rolleyes:

As for your second point? Some insurance companies, once aware that charges are pending, will wait for the outcome of that charge, before apportioning blame.

Henry Ford III

Gophur wrote: »

The Rules of the Road are not the same as the Law of the Land.

It is legal to pass on the Left, but that's not to say a fine member of our constabulary would attempt to prosecute you on the basis of Careless driving (or similar), where you will be up before some old fogie of a Judge who knows SFA about driving.

It's not legal to pass on the left!!!! Nor is it a judgement call.

Just because somebody is driving poorly/ignorantly by hogging a lane, it doesn't give anybody else a carte blanche to compound the error by undertaking them.

opinion guy

Tipp Man wrote: »

Why undertake at all?? Why not move into overtaking lane and flash/horn the guy who is going slow

I really really hate undertaking, probably as much as people driving slow on the overtaking lane, but undertaking is probably more dangerous

Tipp Man wrote: »

I do most of my driving on motorway and if you keep flashing they pull over, its pretty simple and a lot less dangerous

Completely disagree. Coming up behind people and flashing them is very dangerous. It makes people feel pressured and more likely to do something stupid. Oh its also illegal and you can be done for it.

Gophur

Henry Ford III wrote: »

It's not legal to pass on the left!!!! Nor is it a judgement call.

Just because somebody is driving poorly/ignorantly by hogging a lane, it doesn't give anybody else a carte blanche to compound the error by undertaking them.

So, the maximum speed of all traffic in the LH lane is determined by the slowest vehicle in the RH lane? (subject to the local speed limit)

Gophur

opinion guy wrote: »

........ Oh its also illegal and you can be done for it.

Illegal to flash your lights? I don't think so!


Going back to the ROTR, last time I read it. A flash of your lights indicates your presence. Nothing more, nothing less.

galwaytt

Henry Ford III wrote: »

It's not legal to pass on the left!!!! Nor is it a judgement call.

OK, proof please, if the ROTR are deficient, then time to show where it is specifically, illegal.

Henry Ford III wrote: »

Just because somebody is driving poorly/ignorantly by hogging a lane, it doesn't give anybody else a carte blanche to compound the error by undertaking them.

OK, we seem to have go to a point where we need a definition of undertaking. I would suggest mine, from earlier i.e. a maneouvre of lane changing, and changing back.

Having two lanes travelling in the same direction, and at different speeds (for whatever reason), and one stream moving ahead of the other, does not constitutue under - or over - taking by either lane, if no lane-changing maneouvre is made. That's my 0.02.

plissken

Tipp Man wrote: »

With that kind of attitude your worse than the slow guys in the overtaking lane and sum up in a nutshell why Irish drivers have no clue how to drive on a motorway

I do most of my driving on motorway and if you keep flashing they pull over, its pretty simple and a lot less dangerous

Re-read my quote, I clearly asked the question of what to do if they refuse to budge. If they were to remain in the overtaking lane doing 50kmh, would you sit behind them like a sheep or would you carefully, yet swiftfully undertake?

And may I ad that with hundreds of thousands of miles under my belt on motorways/autobahns and american highways and not a single accident, I take offence to your ignorant and ill informed comment regarding my knowledge of driving on a motorway. The reason why so many accidents occur on our roads is due to drivers pedantly sticking to the archaic rules of the road, instead of employing some common sense in how they drive.

Gophur

S.I. No. 182/1997 — Road Traffic (Traffic and Parking) Regulations, 1997

http://www.irishstatutebook.ie/1997/en/si/0182.html

R.O.R

Tipp Man wrote: »

Why undertake at all?? Why not move into overtaking lane and flash/horn the guy who is going slow

Last time I tried that was on the M50 a few years ago, before the lower speed limit came in to effect, around 11pm in the evening. The Micra doing 80km/h in the outisde lane decided that me flashing her obviously meant she was to do an emergency stop in the outside lane.

Thankfully, I had the escape route of the inside lane already in mind and took to it without too major a swerve.

Nowadays I will just keep to the inside lane at, or below the speed limt - but only if I can see that the hard shoulder or lane further inside me is clear, just in case. I know it's wrong, but it is less frustrating (and in my experience, safer) than sitting behind and flashing.

PeakOutput

Gophur wrote: »

I admire your innocence. Don't you know , in such an event, the Insurance companies would nail both parties. Better to have two parties lose their NCB, than one! :rolleyes:

i worked in claims for 3 years

unless it is actually 50-50 blame or there are different versions of events with no independant witness's to back up one or the other then the insurance company will apportion blame as its meant to be apportioned. in this case 100 against the kangoo

As for your second point? Some insurance companies, once aware that charges are pending, will wait for the outcome of that charge, before apportioning blame.

only if there is a point of dispute and the pending decision will give them a firm grounding on which side is correct.

for example if someone is speeding on a main road and a third party pulls out in front of them the speeding, while it may get prosecuted, is irrelevant and the third party is fully liable

glaston

So say I'm on a dual carriage way and both lanes to come to a standstill. If I was in the left lane and traffic in my lane started moving (but not in the right hand lane) am I overtaking?

During driving lessons I was told that you should never cross a white line without checking its safe to do so.

According to some of the arguments here I cound go out onto the M50 now, get my car into the rh lane and then swerve into the lh lane without checking - any damage done wouldnt be my fault!!

Tipp Man

plissken wrote: »

Re-read my quote, I clearly asked the question of what to do if they refuse to budge. If they were to remain in the overtaking lane doing 50kmh, would you sit behind them like a sheep or would you carefully, yet swiftfully undertake?

And may I ad that with hundreds of thousands of miles under my belt on motorways/autobahns and american highways and not a single accident, I take offence to your ignorant and ill informed comment regarding my knowledge of driving on a motorway. The reason why so many accidents occur on our roads is due to drivers pedantly sticking to the archaic rules of the road, instead of employing some common sense in how they drive.

Well for starters you rarely, if ever get people in the outside lane doing 50k - I have never seen it, you do however get people doing 100k in the outside lane, which is infuriating, but from my experience if you flash them they will pull in 9 times out of 10. If not then flash a second time and until they do pull it, its pretty simple

You want to fix bad driving (i.e slow in outside lane) with more bad driving by undertaking. By flashing you are reminding the slow car exactly where they are and the chances are that having flashed them they will be more vigilent for the rest of their motorway journey and much less likely to hog the slow lane, kind of an education process

By undertaking you are compounding the terrible motorway driving in this country, 2 wrongs don't make a right, no matter how many miles you've driven on motorways. And the rules of the road are there for a reason, don't be so ignorant to think you are above them

seamus

Tipp Man wrote: »

but from my experience if you flash them they will pull in 9 times out of 10. If not then flash a second time and until they do pull it, its pretty simple

In my experience, this never works on the M50. Ever.

Absurdum

Tipp Man wrote: »

Well for starters you rarely, if ever get people in the outside lane doing 50k - I have never seen it, you do however get people doing 100k in the outside lane, which is infuriating, but from my experience if you flash them they will pull in 9 times out of 10. If not then flash a second time and until they do pull it, its pretty simple

I have seen it a few times. In my experience, flashing someone usually results in them braking, giving a middle finger, or generally being even more annoying.

You want to fix bad driving (i.e slow in outside lane) with more bad driving by undertaking. By flashing you are reminding the slow car exactly where they are and the chances are that having flashed them they will be more vigilent for the rest of their motorway journey and much less likely to hog the slow lane, kind of an education process

if the slow car needs to be reminded in the first place, they probably have no idea how a motorway is supposed to work

By undertaking you are compounding the terrible motorway driving in this country, 2 wrongs don't make a right, no matter how many miles you've driven on motorways. And the rules of the road are there for a reason, don't be so ignorant to think you are above them

he/she just wants to make progress...