M40 motorway redesignation and demand management system [works ongoing]

Treehelpplease · 06-05-2021 4:03pm

Does it say city centre too? That would be a very useful one, same with Douglas and Wilton.

marno21 · 06-05-2021 4:09pm

Treehelpplease wrote: »

Does it say city centre too? That would be a very useful one, same with Douglas and Wilton.

Yes indeed. City (N27) is displayed on the one at St Finbarrs, N27 coming from the Airport and westbound after the Douglas on ramp.

There’ll likely be more possibilities in future as the infrastructure around Dunkettle is commissioned.

Treehelpplease · 06-05-2021 4:18pm

It's a shame they have City rather than City Centre but I guess that doesn't affect the usefulness. Thanks!

EnzoScifo · 06-05-2021 7:20pm

I wonder if the N40 will ever be redesignated as a motorway at this stage. Maybe they are waiting for Dunkettle to finish.

Treehelpplease · 06-05-2021 7:46pm

I just saw some of them. The sign by the Douglas on ramp has the city centre, airport and N40 J1 (N22). The off ramp by Rochestown/Bloomfield has an M8 junction. The N28 one by Maryborough hill has N40 J6 (city centre?) and one other one I forget

Chris_5339762 · 06-05-2021 8:53pm

Saw all that tonight. However, I'd say its a little aspirational to get from the Togher junction to the City Center in 4 minutes (well, maybe) but certainly not from the Togher junction to the Airport in 5 minutes.

Certainly think the eastbound ones need to show Little Island, but certainly more than "M8 Junction 18: Delays". Give us a number please!

Overall a good start, but having been used to the M50 ones, theres still a bit of improvement to go.

Edit: Whats written on them shows up here -> https://traffic.tii.ie/ Just zoom in.

Treehelpplease · 06-05-2021 9:20pm

Based off of that, all of the city centre messages have been removed except ones saying N40 J6

EDIT: It's back but airport is gone now and Ringaskiddy

Chris_5339762 · 06-05-2021 9:32pm

They probably need a certain amount of traffic to put them up. I'm guessing 930pm on a Thursday night isn't enough!

KrisW1001 · 07-05-2021 9:49am

Here's how it works:

At each gantry, automated Number Plate Recognition (ANPR) cameras read the plates of all the cars that pass under it. A selection of these number-plates, along with the time when they were seen, is passed to the other gantries on the road (this happens via a non-public data network). When these cars pass under another gantry, the same kind of ANPR camera at that gantry reads the number-plates it can see, and cross-references the numbers it has just seen with what the other gantries have seen previously.

By taking an average of how long it was between each number-plate being read at Gantry A to being read at Gantry B, the system can work out the average time of travel between those two points. For destinations beyond the road, it can add an average journey time based on time of day or other traffic information, but most of these systems will just tell you the travel time between junctions on the road itself, as that's a more accurate estimate.

If there aren't enough cars on the road, then the calculations aren't very useful, because they only tell you how fast people are choosing to drive, not how much they're being slowed down by the traffic. In that case, the signs will either display a minimum travel time (based on driving at below the speed limit) or just don't say anything at all.

For data protection reasons, the number-plate information is not retained, but it is usually possible for the Gardaí to request an alert if a number plate that they're interested in appears anywhere on the road.

cantalach · 07-05-2021 4:43pm

KrisW1001 wrote: »

At each gantry, automated Number Plate Recognition (ANPR) cameras read the plates of all the cars that pass under it. A selection of these number-plates, along with the time when they were seen, is passed to the other gantries on the road (this happens via a non-public data network). When these cars pass under another gantry, the same kind of ANPR camera at that gantry reads the number-plates it can see, and cross-references the numbers it has just seen with what the other gantries have seen previously.

I opened a privacy/GDPR case with their designated officer last summer. This went on for a couple of months, during which time she went back to their security consultants to get answers, though they refused to answer some questions for me citing security reasons. But the gist of what she told me is not what you've said above. So I'm very interested to know how certain you are about the accuracy of your information. Were you directly involved in the software implementation?

She told me that the number plates are not themselves transmitted from the gantry. Instead, it transmits a "unique identifier" derived from the number plate. I took this to mean a one-way cryptographic hash (e.g. SHA2-256) of the number plate but she said she couldn't confirm details. I wasn't even happy to hear that because, depending on specific implementation details, it could be very easy to figure out the original number plate from the hash. Hashing can be a very ineffective way to protect privacy when the range of possible inputs is very small (YYY-CC-NNNNN).

Incidentally, the whole business of data not being retained doesn't wash with me. Stuff gets written to log files, log files don't get rolled over, etc.

Limerick74 · 07-05-2021 6:37pm

cantalach wrote: »

I opened a privacy/GDPR case with their designated officer last summer. This went on for a couple of months, during which time she went back to their security consultants to get answers, though they refused to answer some questions for me citing security reasons. But the gist of what she told me is not what you've said above. So I'm very interested to know how certain you are about the accuracy of your information. Were you directly involved in the software implementation?

She told me that the number plates are not themselves transmitted from the gantry. Instead, it transmits a "unique identifier" derived from the number plate. I took this to mean a one-way cryptographic hash (e.g. SHA2-256) of the number plate but she said she couldn't confirm details. I wasn't even happy to hear that because, depending on specific implementation details, it could be very easy to figure out the original number plate from the hash. Hashing can be a very ineffective way to protect privacy when the range of possible inputs is very small (YYY-CC-NNNNN).

Incidentally, the whole business of data not being retained doesn't wash with me. Stuff gets written to log files, log files don't get rolled over, etc.

Any particular reason you are so concerned about the N40 system? Don’t think TII have any interest in spying on anyone and just want to assist drivers.

cantalach · 07-05-2021 7:12pm

Limerick74 wrote: »

Any particular reason you are so concerned about the N40 system? Don’t think TII have any interest in spying on anyone and just want to assist drivers.

I agree, and I'm not concerned about TII uses of the data. My two concerns are scope creep outside of TII (look no further than what happened with the PSC) and data breaches.

I work in cybersecurity and I'm a privacy freak. If I get in my car and make a journey that includes the N40, there should be no record of that anywhere. That is my business and nobody else's.

BelfastVanMan · 07-05-2021 7:21pm

cantalach wrote: »

I agree, and I'm not concerned about TII uses of the data. My two concerns are scope creep outside of TII (look no further than what happened with the PSC) and data breaches.

I work in cybersecurity and I'm a privacy freak. If I get in my car and make a journey that includes the N40, there should be no record of that anywhere. That is my business and nobody else's.

Couldn't agree more.

Aontachtoir · 07-05-2021 9:53pm

cantalach wrote: »

I agree, and I'm not concerned about TII uses of the data. My two concerns are scope creep outside of TII (look no further than what happened with the PSC) and data breaches.

I work in cybersecurity and I'm a privacy freak. If I get in my car and make a journey that includes the N40, there should be no record of that anywhere. That is my business and nobody else's.

Well, except for the phone company which tracks your phone wherever it goes. And every traffic camera you pass by. And other drivers with dash cams, pedestrians taking photos or movies on their phones, CCTV in front of shops and banks, etc etc.

It's hard to see what the risks are to me or you from mission creep on this, to be honest. Same with data breaches in such a specific context.

cantalach · 07-05-2021 11:13pm

Aontachtoir wrote: »

Well, except for the phone company which tracks your phone wherever it goes. And every traffic camera you pass by. And other drivers with dash cams, pedestrians taking photos or movies on their phones, CCTV in front of shops and banks, etc etc.

Yes, yes, of course. But I can only do something about things that I can do something about. If my roof is leaking in five places but I only have two buckets, I'm still going to use the two buckets.

It's hard to see what the risks are to me or you from mission creep on this, to be honest.

You nailed it!

That is precisely why it is called creep. We don't see the risks because the change happens so slowly, one little erosion at the time.

Same with data breaches in such a specific context.

Not sure I follow your point there, but I think that data with the potential to reveal details of somebody's car journeys is something you would want to guard very closely indeed.

Aontachtoir · 08-05-2021 12:51am

cantalach wrote: »

Yes, yes, of course. But I can only do something about things that I can do something about. If my roof is leaking in five places but I only have two buckets, I'm still going to use the two buckets.

You nailed it! That is precisely why it is called creep. We don't see the risks because the change happens so slowly, one little erosion at the time.

Not sure I follow your point there, but I think that data with the potential to reveal details of somebody's car journeys is something you would want to guard very closely indeed.

Well, if it makes you feel more in control. It just seems that people tracking you through time-to-destination cameras on the N40 is such a small risk compared to the other options, like through your phone, I don't understand why it's worth worrying about. Same with "mission creep", which seems so nebulous and ill-defined that the only way to prevent it is to never change.

Either way, I guess we'll have to get used to them. Once Covid ends the appalling traffic will come roaring back, and if the variable limits on the M50 increase capacity I am sure there will be calls to do it in Cork too.

I know the legislation allowing for the M50 to become a "smart" motorway specifically carves out the M50, but has anyone heard anything about applying things like that to the N40?

KrisW1001 · 08-05-2021 9:24am

cantalach wrote: »

I opened a privacy/GDPR case with their designated officer last summer. This went on for a couple of months, during which time she went back to their security consultants to get answers, though they refused to answer some questions for me citing security reasons. But the gist of what she told me is not what you've said above. So I'm very interested to know how certain you are about the accuracy of your information. Were you directly involved in the software implementation?

No, but I have had discussions with suppliers of similar systems that are used elsewhere. If there's part of the general mechanism for producing the time estimates that I described that is incorrect, then please feel free to correct it - I'd be interested to hear how the N40 system differs from the ones I know about already.

Regarding the small plaintext space for the plate hashes, this is a longstanding problem, not something that has just come to light just now. There are ways of mitigating this (off the top of my head, plain-text padding using a rolling, pre-shared secret, or you could use symmetric encryption using a rolling key) that will make the data unusable if discovered later in a file-dump, but as you say there's no defence against some tool (in both senses of that word) printing the raw plate numbers to a log file. That's why this stuff is audited by people like you.

As you work in computer security (as I did once) I don't need to tell you that no system is impervious to leakage and all you can do is reduce the opportunity, ease and consequence of attacks via that software.

I understand your professional concerns about the system security, but I don't agree with the premise that there's any right to privacy on the public road in the first place. Especially not when so many other drivers use dash-cams that continuously record traffic.

Markcheese · 08-05-2021 6:58pm

I suppose part of the issue is intent - if you put up traffic cameras or an anpr system and say it's for x purpose and works this way - and the general population is fine with that - then whoopy do - ( say the anpr is only to logs cars that are on a garda watch list, and no other data is kept ) , but what if it turns out later that all car movements are actually logged and stored , for some non specified nefarious purpose? )

Treehelpplease · 11-05-2021 6:01pm

There are delays on the road and all the signs say are "delays". Despite this, the Maryborough hill sign says 4 minutes to the city centre, as does the Frankfield sign, the Wilton sign and the Douglas west on ramp sign

marno21 · 28-05-2021 12:03pm

Work ongoing this week to provide power to the last remaining non-Dunkettle sign just before J1 on the Ballincollig bypass. That'll be the N40 set of signs complete then.

Work continues on the signs in the vicinity of Dunkettle.

blindsider · 29-05-2021 11:22pm

When it rains, ALL the signs say "Surface Water" or similar - no traffic info.

I presume they'll improve this 'info' by November or we'll be reading that 3 days a week.

Couldn't every 2nd sign read "Surface Water", or alternate it with the timings info every 3 seconds?

Chris_5339762 · 30-05-2021 11:52am

The M50 signs do the same, which is very annoying. Every single one of them.

Treehelpplease · 30-05-2021 4:39pm

i emailed TII about changing "city" to "city centre" and they said it is standard across Ireland to refer to the city centre as city on those signs. they said they're also not supposed to be taken as direction signs and more just to inform people if they are going the route how long it will take. a lot seem pointless right now as the figures just don't matter. whenever it is heavy, it says delays and that is useless as generally if one junction has a delay they all do.

Chris_5339762 · 31-05-2021 11:22am

All of the signs saying "CAUTION: FOG" this morning. Lovely visibility everywhere, not sure who thought that one up!

hans aus dtschl · 02-06-2021 2:48pm

Chris_5339762 wrote: »

All of the signs saying "CAUTION: FOG" this morning. Lovely visibility everywhere, not sure who thought that one up!

It was referring to the usefulness of the signs themselves, not the weather conditions.

"Nebulous"

cantalach · 05-06-2021 10:44am

hans aus dtschl wrote: »

It was referring to the usefulness of the signs themselves, not the weather conditions.

"Nebulous"

"Not clear"

M40 motorway redesignation and demand management system [works ongoing]

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