Dublin Bus vehicle maintaining very low average speed

n97 mini

Are DB drivers being rewarded for driving slowly? We left Westmoreland St about 30 seconds behind another bus on the same route. I'm used to buses leap frogging each other when that happens, but the bus in front left us for dust. We only stopped 3 times over the next 10 miles (bus in front was mopping) but we arrived about 12-15 minutes later than usual.

I hope this isn't going to be a regular occurrence.

(Bus was new-ish and didn't seem to be suffering from any problems)

StreetLight

Maybe it was a new driver being extra cautious?

n97 mini

Occurred to me aswell. Possible. He was in his 50s.

s8080

what was the route, and at what time.
give us bus workers a bit of info and we might be able to give answer

frankyboy1986

n97 mini wrote: »

Are DB drivers being rewarded for driving slowly?

Driving Slowly = No
Driving Safely = Yes

n97 mini

Did I read somewhere that part of the recent settlement with drivers included a reward for saving fuel?

LXFlyer

Your bus might have had long running time with an extended wait at the terminus. The driver may have preferred driving slowly rather than sitting at the terminus.

n97 mini

That occurred to me too. The passengers would have preferred to get home in a timely fashion rather than sit on a slow moving bus!

macroman

If they had caught the bus in front the could well be ahead of schedule, so the controller could have requested them to ease back or the driver decided on their own initiative to ease back to regain even headway.

cdebru

n97 mini wrote: »

That occurred to me too. The passengers would have preferred to get home in a timely fashion rather than sit on a slow moving bus!

I think this is funny because aren't people here always complaining about buses being early ? Aren't the NTA pushing for even headway? You can't have it both ways either you want buses to be regular and take the same time irrespective if traffic or you want the bus to complete the journey as quickly as possible, it is one or the other, even headways and regular journey times mean that at times buses will deliberately be slowed and may have waits at timed points along the route.

People should be careful what they look for the days of leap frogging and getting into town 30 minutes early because the kids are off school are fast coming to an end if it regularly takes an hour then an hour it will take even when traffic is light or a bus is just in front.

n97 mini

I think it's funny how people will defend DB/IE/BE to the last, even when the OP states the journey took 12-15 mins longer than usual.

cdebru

n97 mini wrote: »

I think it's funny how people will defend DB/IE/BE to the last, even when the OP states the journey took 12-15 mins longer than usual.

Was the bus late arriving at the terminus ?

See this is exactly what you and others are looking for, but apparently only when it suits you, so if you want to pick the bus up along the route you want it to follow a predictable timing as to when it should arrive at given stops but if you are on the bus you want it to leapfrog and get you to your destination asap. So the driver drives out at normal speed, "its a disgrace a bus arriving early" the driver operates slowly so as to not arrive early and " its a disgrace I should have been home 12 or 15 minutes ago" You have just shown that no matter what is done even if it is something you have asked for DB will be wrong in your eyes, well done.

You can't have it both ways.

But to answer your original question are drivers being rewarded for driving slowly, well not above their normal reward ie their wages, but they are at the request of the NTA being told to drive slowly even if the road is empty and there are no passengers so as to keep even headway, ie keep the same relative distance (time) between buses on the same route. This will involve journeys taking longer than "usual"

coylemj

Isn't there an elephant in the room here....

There was a program on RTE TV a few years ago in which they spoke to former DB drivers, one of whom pointed out that on many occasions he was aware of drivers deliberately driving slowly so that when they arrived back at the depot, there wouldn't be enough time on their schedule for them to be sent out again. The trade union rep. naturally denied this and as ammunition he used the fact the guy had 'only' worked in DB for six months so clearly he hadn't a clue what he was talking about!

I have been on buses that drove at breakneck speed and on other occasions at a snail's pace, including having long chats with auld wans and tourists at bus stops while the rest of us sat there fuming. Doesn't happen too often but does happen.

About two months ago I was on a 46A heading towards town, I needed to make a connection at UCD but missed it because the driver drove as slowly as he could and he wasn't doing so because the depot told him to in order to optimize the service, we were passed out by three 46As between White's Cross and UCD because he was going so slow.

Alun

cdebru wrote: »

See this is exactly what you and others are looking for, but apparently only when it suits you, so if you want to pick the bus up along the route you want it to follow a predictable timing as to when it should arrive at given stops but if you are on the bus you want it to leapfrog and get you to your destination asap.

Do we? I don't. I want it to arrive when it's supposed to arrive, there's no advantage to me personally if I get there early. It will also have the advantage that I won't need 5 minutes rest at the end of the journey to recover from feeling travel sick because the driver has been hurling the bus around like it was a rally car.

n97 mini

cdebru wrote: »

the driver operates slowly so as to not arrive early and " its a disgrace I should have been home 12 or 15 minutes ago"

You're not getting it, deliberately so I suspect. 12-15 minutes LATER than usual is LATE.

cdebru

n97 mini wrote: »

You're not getting it, deliberately so I suspect. 12-15 minutes LATER than usual is LATE.

No its not, its late only if he hasn't arrived by the time he is timetabled to arrive which depending on the driver,route, day, time of day could be 10 or 20 minutes longer than it normally takes to do that journey.

cdebru

coylemj wrote: »

Isn't there an elephant in the room here....

There was a program on RTE TV a few years ago in which they spoke to former DB drivers, one of whom pointed out that on many occasions he was aware of drivers deliberately driving slowly so that when they arrived back at the depot, there wouldn't be enough time on their schedule for them to be sent out again. The trade union rep. naturally denied this and as ammunition he used the fact the guy had 'only' worked in DB for six months so clearly he hadn't a clue what he was talking about!

I have been on buses that drove at breakneck speed and on other occasions at a snail's pace, including having long chats with auld wans and tourists at bus stops while the rest of us sat there fuming. Doesn't happen too often but does happen.

About two months ago I was on a 46A heading towards town, I needed to make a connection at UCD but missed it because the driver drove as slowly as he could and he wasn't doing so because the depot told him to in order to optimize the service, we were passed out by three 46As between White's Cross and UCD because he was going so slow.

There are a couple of things in there, one is peoples perception, so for example if you are under pressure to get to work, catch a flight then the same journey can appear to you to be slow but to someone older or less firm on their feet the driver looks like he is training for formula one.

Second is lazy ****ers every job has them and DB is no different in that regard, but those drivers are even less popular with their "colleagues" than they are with the poor passengers who have to endure their attempts to avoid working, remember at the end of the day some other driver ends up doing their work for them.

Thirdly is competing demands different sections of DB want different things so the training school and driver monitors want slow, because their main concern is safety but the controllers they like fast because they want the timetable to be met, and the NTA wants slow and fast depending.

Most drivers find a happy medium I think, but it is over 2000 drivers so some will drive slow not to avoid work but because that is what they are comfortable with and some will drive fast, until they have an accident and they either cop themselves on or they find another job.

n97 mini

cdebru wrote: »

No its not, its late only if he hasn't arrived by the time he is timetabled to arrive

And as DB don't publish arrival times, we customers go on the time that departure normally arrives.

cdebru

n97 mini wrote: »

And as DB don't publish arrival times, we customers go on the time that departure normally arrives.

2 minutes before next departure is official arrival time in practice next departure time is still on time.

Peppa Pig

cdebru wrote: »

2 minutes before next departure is official arrival time in practice next departure time is still on time.

Does that mean that as long as the last bus of the day arrives before the first departure next morning it is on time?

n97 mini

cdebru wrote: »

2 minutes before next departure is official arrival time in practice next departure time is still on time.

I think you're making stuff up now!

end of the road

coylemj wrote: »

Isn't there an elephant in the room here....

There was a program on RTE TV a few years ago in which they spoke to former DB drivers, one of whom pointed out that on many occasions he was aware of drivers deliberately driving slowly so that when they arrived back at the depot, there wouldn't be enough time on their schedule for them to be sent out again. The trade union rep. naturally denied this and as ammunition he used the fact the guy had 'only' worked in DB for six months so clearly he hadn't a clue what he was talking about!

I have been on buses that drove at breakneck speed and on other occasions at a snail's pace, including having long chats with auld wans and tourists at bus stops while the rest of us sat there fuming. Doesn't happen too often but does happen.

About two months ago I was on a 46A heading towards town, I needed to make a connection at UCD but missed it because the driver drove as slowly as he could and he wasn't doing so because the depot told him to in order to optimize the service, we were passed out by three 46As between White's Cross and UCD because he was going so slow.

how do you know he wasn't told to do so

end of the road

n97 mini wrote: »

I think you're making stuff up now!

or maybe you don't like and can't except what he's telling you. thats fine, but doesn't mean he's "making stuff up"

n97 mini

end of the road wrote: »

or maybe you don't like and can't except what he's telling you. thats fine, but doesn't mean he's "making stuff up"

I'll give you an example to get you going: the 239. Journey time 46 minutes, but the 13.30 Saturday departure is still "on time" as long as it arrives less than 2 hours 58 minutes later? Good man if you swallow that

cdebru

Peppa Pig wrote: »

Does that mean that as long as the last bus of the day arrives before the first departure next morning it is on time?

No the bus has a departure time to return to the depot so if it arrives at or before that time it is on time if the bus is due back out at 11.30 then its official arrival time is 11:28

end of the road

n97 mini wrote: »

I'll give you an example to get you going: the 239. Journey time 46 minutes, but the 13.30 Saturday departure is still "on time" as long as it arrives less than 2 hours 58 minutes later? Good man if you swallow that

thats not what he said and meant, and you know it.

cython

n97 mini wrote: »

And as DB don't publish arrival times, we customers go on the time that departure normally arrives.

cdebru wrote: »

2 minutes before next departure is official arrival time in practice next departure time is still on time.

A nice idea in theory, but then you post this:

cdebru wrote: »

No the bus has a departure time to return to the depot so if it arrives at or before that time it is on time if the bus is due back out at 11.30 then its official arrival time is 11:28

Which means that these so-called arrival times are still no use to the customer, and we are back to the first post I quoted in terms of customer information w.r.t. arrival times, i.e. none are published, at least not in the customers' view. Once you get there, you have 2 options for determining arrival times; either it's to be based off the estimated journey times on timetables (which reality can vary wildly from) or simply experience/the "normal" time.

n97 mini

end of the road wrote: »

thats not what he said and meant, and you know it.

It is:

2 minutes before next departure is official arrival time in practice next departure time is still on time.

Obviously rubbish.

The fact remains that the "on time" is what it typically is, or if not it's what's on the timetable, and none of 2 minutes BS.

coylemj

end of the road wrote: »

how do you know he wasn't told to do so

Oh I see, so if he was told to do so, then what you're saying is that a driver with 40 or so passengers on board was officially told to slow down to the extent that he was passed out by three other buses serving the same route and which departed the terminus later? Is that what you're saying?

Or is there some other motive behind your question - like that there must be some other explanation that doesn't involve a maverick driver taking the p1ss with a load of passengers on board?

AlekSmart

n97 mini wrote: »

I think it's funny how people will defend DB/IE/BE to the last, even when the OP states the journey took 12-15 mins longer than usual.

How do you arrive at this "Defending to the Last" stance ?

In all fairness,you pose a question....

n97 mini : Are DB drivers being rewarded for driving slowly?

followed by a somewhat pointed statement...

I hope this isn't going to be a regular occurrence.

NO,they are not.
YES,it is going to be a regular occurence.

The answers since,have been largely factual and whilst maybe not what you wanted to hear,remain perfectly valid.

It has even been pointed out how the NTA are now focusing strongly on the Maintenance of Headway on routes,something which is largely impossible in the Dublin context until Luas BXD works finish.

However,this has not prevented the NTA from making forays into the business of route regulation with enquiries and recommendations to introduce en-route "Timing Points",all of which will come eventually.

It would not be unusual in London,for example,to be on a bus driven in a slow manner and delaying at each Bus-Stop in response to a controllers Regulation Instruction,usually this will end with passengers being advised to "All-Change" onto a following Bus with the original bus then turning short to regain timetable placing.

This is the regulatory & control system as envisaged by the NTA and will most likely become the norm in Dublin.

However,it has to be realized that this type of regulation relies on routes being relatively short distance (Significantly less than the 10 Miles mentioned in the OP) and high-frequency for acceptable customer satisfaction levels to be maintained.

Whether the NTA intends to resource Dublin Bus services to this level remains to be seen.

Very few current Dublin Bus schedules are frequent enough to allow
for this type of regulation,but that won't prevent the experiment continuing until the inevitable conclusion is reached.

I'm still unclear where the "Defending DB" is coming from

The most likely explanation of the OP is the "Cautious New Driver"....

n97 mini: Occurred to me as well. Possible. He was in his 50s.

The drivers apparent age has little relevance,as several new starts over the past few months would be in their 50's.

cdebru

n97 mini wrote: »

I'll give you an example to get you going: the 239. Journey time 46 minutes, but the 13.30 Saturday departure is still "on time" as long as it arrives less than 2 hours 58 minutes later? Good man if you swallow that

If the normal journey time is 46 minutes ie time for same bus to depart terminus A and then depart terminus B to return to terminus A then the arrival time is 44 minutes after the departure time from A and vice versa, I dont know the 239 but I would imagine that the 13:30 is due at the terminus at 14:14 then returns to depot for drivers break then returns to terminus for next journey at 15:30 or whatever time.
But in the normal course where the same bus is traversing back and forth between termini then the arrival time is 2 minutes before its next departure, if it is returning to the depot then it's arrival time is usually the normal total journey time less 2 minutes, ( although schedulers sometimes cut running time on a breaking or finishing journey)

cdebru

n97 mini wrote: »

It is:



Obviously rubbish.

The fact remains that the "on time" is what it typically is, or if not it's what's on the timetable, and none of 2 minutes BS.

No you asked what is the arrival time and as per the drivers board the arrival time is 2 minutes before his next scheduled departure unless obviously where the driver is due to take the bus back to the depot in which case he has an arrival time to the terminus followed by time he is due to be in the depot to finish or break.

No BS those are the facts, whether you like it or not.

cdebru

cython wrote: »

A nice idea in theory, but then you post this:


Which means that these so-called arrival times are still no use to the customer, and we are back to the first post I quoted in terms of customer information w.r.t. arrival times, i.e. none are published, at least not in the customers' view. Once you get there, you have 2 options for determining arrival times; either it's to be based off the estimated journey times on timetables (which reality can vary wildly from) or simply experience/the "normal" time.

But the bus always has an official arrival time it can arrive before after or on that time, but it still has an official arrival time and it is not late unless it arrives after that time and in practice it is not late unless it arrives after its next scheduled departure which is in the normal course excepting when the bus has to return to the depot 2 minutes after its official arrival time.
Now in practice on different routes at different times a bus may "normally" arrive well in advance of its official arrival time, but it is not late when it doesn't and the NTA want buses to arrive at or near its arrival time which in practice all being well a bus should use up its full running time irrespective of traffic or loading, the downside to that is if a problem arises towards the end of the journey there is no recovery time because it has been used up by stopping buses along route or requesting buses to slow down, and the next departure for that bus may have to be canceled or the bus curtailed. The NTA haven't worked that bit out yet.

n97 mini

From a customer perspective it doesn't matter what's on the driver's board. If it arrives later than it usually arrives, from the customer's perspective it's late.

cdebru

n97 mini wrote: »

From a customer perspective it doesn't matter what's on the driver's board. If it arrives later than it usually arrives, from the customer's perspective it's late.

Perspective is not reality, the reality is a bus has x amount of time to do a journey it may regularly do that journey in less time but, unless it uses more time it is not late, it is later than it regularly is, and with the NTA pushing for even headways buses ahead of scheduled arrival will be less and less which is what you actually want, regular journey times irrespective of traffic, which means the bus will take the longer even if quicker journeys are possible.

mmmcake

The bus was waiting at the terminus this morning so i was talking to the driver and i showed him this discussion.
He said it could be to do with engine emissions, something called Add Blue, when its not working properly it limits the top speed to cut engine emissions, he said bus can only crawl along.

cdebru

mmmcake wrote: »

The bus was waiting at the terminus this morning so i was talking to the driver and i showed him this discussion.
He said it could be to do with engine emissions, something called Add Blue, when its not working properly it limits the top speed to cut engine emissions, he said bus can only crawl along.

Shouldn't be driven with no adblue, driver would be liable to a fine of upto €1000 for a first offence if found driving without adblue, you would hope a professional driver wouldn't be silly enough to continue a journey with the bus in limp home mode.

LXFlyer

This thread does highlight the manner in which buses are scheduled in Dublin.

There has been an improvement in the scheduling of buses since Network Direct, for example on the Lucan QBC the 25a/25b are scheduled in such a way to offer an integrated service along the core section of the route (from Merrion Square to Foxborough and v.v.), and the 26, 66/a/b and 67 have integrated schedules outbound (every 15 minutes to Leixlip all day, and every 7-8 minutes to Palmerstown).

At the same time in order to come up with RTPI information, full timing estimates for every stop have been produced for every departure on every route. However, these are precisely that- estimates and they are not timetables.

The only real timetables in place are, as cdebru states, the public departure times from the terminus, and (where appropriate) additional entries on the drivers' running boards for:
- Departure times from the depot
- Driver changeovers (can be mid-route)
- Buses being parked at bus stands while driver breaks take place
- Times for returning to depots from termini
- Finishing times at the depot

The 84 is an exception to this as it is timed at Bray Station.

Apart from this are no official timing points for any bus routes mid-route.

The whole timetable design is predicated on departure times from the terminus. The official line is that the arrival time is 2 minutes before the next departure time (or whatever time the bus is timed to leave to go back to the depot as appropriate).

Now the reality is that the schedulers are making an effort to deliver timetables that:

1) Deliver regular interval departures from the termini
2) Deliver even headway between buses along the route

This can result in buses having longer layovers at their termini in order to maintain both of these goals. People may see this as inefficient, but ultimately the goal has to be to deliver a consistent service all along the bus route. That frankly is more preferable to going as fast as you possibly can.

The schedulers will also build in recovery time for delays en route (although this is not officially stated).

But, until full working timetables are produced with timed points en route, you are going to have a situation where some drivers may decide to take their time if they know that they may have a long wait at the opposite terminus. And when that is introduced, you have the issue of coming up with realistic timings, safe locations to be regulated at, and the need to ensure that at peak times full buses are not held at stops!

Scheduling buses is now an extremely difficult task particularly when you also add in the issue of complying with the EU Working Time Directive.

There is still a long way to go before we actually see a bus service that delivers a properly integrated network. Network Direct was only the first phase of this. The next phase has to be examining headways on each corridor in both directions, and in the case of cross-city routes, perhaps adding extra departures from the city centre where necessary to keep headways constant.

cdebru

lxflyer wrote: »

This thread does highlight the manner in which buses are scheduled in Dublin.

There has been an improvement in the scheduling of buses since Network Direct, for example on the Lucan QBC the 25a/25b are scheduled in such a way to offer an integrated service along the core section of the route (from Merrion Square to Foxborough and v.v.), and the 26, 66/a/b and 67 have integrated schedules outbound (every 15 minutes to Leixlip all day, and every 7-8 minutes to Palmerstown).

At the same time in order to come up with RTPI information, full timing estimates for every stop have been produced for every departure on every route. However, these are precisely that- estimates and they are not timetables.

The only real timetables in place are, as cdebru states, the public departure times from the terminus, and (where appropriate) additional entries on the drivers' running boards for:
- Departure times from the depot
- Driver changeovers (can be mid-route)
- Buses being parked at bus stands while driver breaks take place
- Times for returning to depots from termini
- Finishing times at the depot

The 84 is an exception to this as it is timed at Bray Station.

Apart from this are no official timing points for any bus routes mid-route.

The whole timetable design is predicated on departure times from the terminus. The official line is that the arrival time is 2 minutes before the next departure time (or whatever time the bus is timed to leave to go back to the depot as appropriate).

Now the reality is that the schedulers are making an effort to deliver timetables that:

1) Deliver regular interval departures from the termini
2) Deliver even headway between buses along the route

This can result in buses having longer layovers at their termini in order to maintain both of these goals. People may see this as inefficient, but ultimately the goal has to be to deliver a consistent service all along the bus route. That frankly is more preferable to going as fast as you possibly can.

The schedulers will also build in recovery time for delays en route (although this is not officially stated).

But, until full working timetables are produced with timed points en route, you are going to have a situation where some drivers may decide to take their time if they know that they may have a long wait at the opposite terminus. And when that is introduced, you have the issue of coming up with realistic timings, safe locations to be regulated at, and the need to ensure that at peak times full buses are not held at stops!

Scheduling buses is now an extremely difficult task particularly when you also add in the issue of complying with the EU Working Time Directive.

There is still a long way to go before we actually see a bus service that delivers a properly integrated network. Network Direct was only the first phase of this. The next phase has to be examining headways on each corridor in both directions, and in the case of cross-city routes, perhaps adding extra departures from the city centre where necessary to keep headways constant.

Unfortunately integrating the timetable in one direction still leaves you with huge gaps in the other direction as buses travel in convoy due to silly timings, the problem is that DB doesn't have any " professional" schedulers, like you say it is a difficult task to balance all the competing demands and that needs professional people who understand the complexities and can deliver in a timely manner ie not years and years to get a timetable changed.

Timing points seem like a good idea but I suspect the reality would be that they would be timed to slow the fastest of drivers and most buses would never make it to the timing points ahead of schedule, otherwise you risk collapsing the whole timetable once a problem anywhere in route happens, too tight a timing for a terminus doesn't work that's what happened to the 4.

LXFlyer

cdebru wrote: »

Unfortunately integrating the timetable in one direction still leaves you with huge gaps in the other direction as buses travel in convoy due to silly timings, the problem is that DB doesn't have any " professional" schedulers, like you say it is a difficult task to balance all the competing demands and that needs professional people who understand the complexities and can deliver in a timely manner ie not years and years to get a timetable changed.

Timing points seem like a good idea but I suspect the reality would be that they would be timed to slow the fastest of drivers and most buses would never make it to the timing points ahead of schedule, otherwise you risk collapsing the whole timetable once a problem anywhere in route happens, too tight a timing for a terminus doesn't work that's what happened to the 4.

The whole scheduling process needs a complete overhaul, and that includes being able to correctly interpret data from the AVLC system and to stand back and look at the effect the schedules have on the entire corridor.

cdebru

lxflyer wrote: »

The whole scheduling process needs a complete overhaul, and that includes being able to correctly interpret data from the AVLC system and to stand back and look at the effect the schedules have on the entire corridor.

I agree I think schedules should be done on an entire corridor together, it is pointless trying to maintain headways when those headways actually involve buses running in convoys on main corridors, it is basic things like if one terminus is 10 minutes further up the road then having it depart and then 10 minutes later just as it arrives having a bus depart from the second location so that the two if them can travel in convoy till they meet the next bus and then 3 in a convoy and then no bus along the corridor for 30 minutes, crazy stuff

The_Wrecker

cdebru wrote: »

Shouldn't be driven with no adblue, driver would be liable to a fine of upto €1000 for a first offence if found driving without adblue, you would hope a professional driver wouldn't be silly enough to continue a journey with the bus in limp home mode.

Give me something official on the Adblue fine ~ link etc as this is quite frequent.

cdebru

The_Wrecker wrote: »

Give me something official on the Adblue fine ~ link etc as this is quite frequent.

Google is your friend.


But for the lazy here it is

http://www.rsa.ie/Documents/Vehicle%20Std%20Leg/Information%20Notes/Information%20note%20for%20Euro%20IV%20Euro%20V%20and%20Euro%20VI%20Emissions%20Regulations%20for%20Heavy%20Duty%20Vehicles%20%20Feb%202012.pdf


Thats from the RSA page 6

Penalties for breach of in-use requirements
Vehicles used on Irish roads are required to meet with the Irelands Construction Equipment and Use Regulations S.I. No. 190 of 1963. CE&U Regulations, prescribe the requirements for all vehicles and trailers in use in a public place in Ireland. This includes provisions for but not limited to; the brake systems, exhaust systems, mirrors, safety belts and side and rear underrun
protection.
These Regulations prescribe the requirements as to the construction,equipment and use of vehicles while being used in a public place and the duties of drivers and passengers are also specified. As well as specific provisions for certain aspects of vehicles, the CE&U also has general provisions requiring that a vehicle is maintained in good and efficient working order, that no danger is likely to be caused and that vehicles are maintained such that their level of noise emitted and their emissions does not increase.
Should a vehicle and all its parts and equipment not be maintained in good and efficient working order, then the operator or owner could be considered to be in breach of Regulation 34 of SI 190 of 1963. With regard to emissions, the regulation specifies that there is a duty of care that a vehicle is maintained in such a way that the health of others is not compromised.
Penalties for breach of this regulation is as follows;

on summary conviction, first offence

– a fine not exceeding €1,000. Second offence under same section/subsection – a fine not exceeding €2,000. Third or subsequent offence under same section/subsection within 12 consecutive months – fine not exceeding €2,000 or imprisonment not exceeding 3 months, or both (ss.11(5) and 102, Road Traffic Act, 1961).
The correct functioning of the emissions control systems including the after-treatment system are the basic requirements for fulfilling the established standards for pollutant emissions.
Tampering with systems which control the level of emissions or driving a vehicle without consumable reagent, could be considered to be in breach of the aforementioned regulations and subject therefore to the penalties listed.

Now I even highlighted the important bits for you ;-)

Oh just in case of any confusion as to what consumable reagents are from page 4 same document
Consumable Reagent (AdBlue)