30k speed limits for all urban areas on the way

Flinty997

https://www.boards.ie/discussion/comment/121142985#Comment_121142985

The removal of that car parking was primarily due to pedestrians walking anywhere they wanted to and causing issues on the cycle lane. So they moved the cycle lane to the road.

People have been asking OPW for segregated cycle lanes in the park for a decade or more.

Flinty997

Hope we'll see you all at the bike disco...

https://www.fingal.ie/events/bike-disco

Flinty997

https://www.boards.ie/discussion/comment/121143027#Comment_121143027

You'd have to be mad to go through Castleknock unless you absolutely had to. Always a queue there these days.

SeanW

https://www.boards.ie/discussion/comment/121129784#Comment_121129784

A good piece of propaganda maybe, but not much else. A genuinely "good piece" would explore a concept from a neutral lens, provide background, context etc. Good propaganda on the other hand, starts with the conclusion and works backwards, misleading or deceiving the reader as necessary to support the pre-ordained narrative.

At no point in your "good piece" did it point out that Ireland has among the world's best road safety records or that fatalities are so rare that they can be measured in the low single-digits per billion vehicle kilometres, both of which they could have determined by spending 5 minutes on wikipedia. Nor did it point out that cruising at low speeds like 30kph uses significantly more fuel than at more normal speeds like 50 or 60.

fegov_graph.gif

At no point did it try to estimate how much of people's time and fuel would be wasted by wallpapering main roads with absurdly low limits. And the author straight up lied by claiming that "default" would not be the same a "blanket" as we saw what 30kph as default would look like with Dublin City Councils "Love 30" campaign.

So your "good piece" is really just a collection of carefully chosen arguments, lies of omission and just straight up lies.

kennethsmyth

Why was 40kph not considered ????

Flinty997

So much stop start driving in urban areas that fuel economy is irrelevant. An EV is going to be far more efficient.

Rubberchikken

Instead of focusing on 30 kmh limits which won't be enforced or obeyed they should really crack down on phone use while driving.

I had a dopey one come around the corner weaving over the centre line while talking into her phone which she was waving around in front of her gob because seemingly the utter plank's ears weren't working.

Not much going on in that thick head of hers either.

If I go out in a firey crash I don't want it to be caused by some dim half witted phone user😄

https://www.boards.ie/discussion/comment/121145605#Comment_121145605

Phone use is absolutely a problem, no denying that.

Ok, let's do that, crack down on phone use. Assume we eliminate it as an issue, 100% eliminate it.

Now, for the collisions that will still happen between motor vehicles and pedestrians/cyclists at 50k,how will the severity of those impacts be reduced?

Answer, the severity will not be reduced as this comes down to physics. Getting hit at 30k is way more survivable than getting hit at 50k.

Don't get me wrong, I agree phone use while driving is a problem ghat needs to be tackled and addressing it will reduce the amount of collisions.

However, that does not mean we shouldn't go for the day 30k limit. Simple physics shows the benefits.

magicbastarder

https://www.boards.ie/discussion/comment/121145595#Comment_121145595

In fact, I'd posit that a 30km/h limit could result in *less* fuel burned. Yes, an ICE car is more efficient at 50 than at 30. But being fuel efficient at speed X requires you to reach speed X and hold it there. Accelerating to 50 and having to hit the brakes several seconds after you hit 50 is probably going to burn more fuel than accelerating to 30 and holding it at 30 for a bit longer before you brake.

Or another way; my car is most fuel efficient at around 70 or 80km/h on the open road I reckon. But it'd be madness to assert that the best fuel efficiency I could get in an urban area would involve me hitting 70 or 80 to achieve it.

SeanW

@magicbastarder your argument would be valid if all affected journeys were only in the peak times, and/or only in dense urban environments where there was a need to stop for a yield sign or red light every 100m or so. We both know that this is not true.

@[Deleted User] given that we know that there are more than 300,000,000 vehicle kilometres between fatalities of any kind, and most of those occurring to people inside motor vehicles, we're entitled to ask hard questions. Like, if your point is more theoretical than practical. Or whether we should punish the very small number of people who are actually culpable these incidents, rather than the 2.8 million drivers in Ireland who have nothing whatsoever to do with any of them?

magicbastarder

you clearly have access to information i don't have if you know the optimum maximum speed to drive at in an urban environment.

Flinty997

Not sure it matters if you don't feel the need to stop for yield signs or red lights. Then optimum speed is more about law enforcement.

SeanW

https://www.boards.ie/discussion/comment/121152359#Comment_121152359

What a bizarre comment - of course you have to stop for red lights and yield at yield signs. Point was that "urban areas" run the gamut from dense central areas where these things are common, to areas where you can have "cruise" for long stretches without these things.

https://www.boards.ie/discussion/comment/121151911#Comment_121151911

You view protecting those outside cars as punishment, therein lies the issue

timmyntc

https://www.boards.ie/discussion/comment/121152550#Comment_121152550

There are provisions for speed limits to be raised on trunk roads (or any road for that matter if justified)

These urban but not urban roads you speak of can simply have a higher limit as appropriate. Lower limits are still appropriate for vast majority of urban roads and streets.

SeanW

https://www.boards.ie/discussion/comment/121152559#Comment_121152559

I view forcing 2.8 million people to waste time and fuel crawling for no reason as punitive, yes. And the data are clear that there is basically no reason. Ya know, the data showing more than 300,000,000 vehicle-kilometres between fatalities and those outside cars being the minority.

https://www.boards.ie/discussion/comment/121152622#Comment_121152622

BS. We saw what "30kph as default" would look like with Dublin City Councils' "Love 30" campaign. "Default" is another word for "basically universal."

Seth Brundle

I'm not sure was my earlier post removed but anyhow, it's hardly the mass punishment you claim it to be if the impact is minimal...

https://twitter.com/Amanwy/status/1705945340208116172?t=n_fdwiDCBR80a8adLYLmfw&s=19

magicbastarder

https://www.boards.ie/discussion/comment/121152651#Comment_121152651

please share with us the evidence that maintaining a maximum speed of 30km/h in urban areas wastes fuel.

SeanW

I did, in post 1265. Below 30MPH/50kph your cars fuel efficiency falls off a cliff.

Though we may have differing definitions of "urban area"

magicbastarder

that's the fuel efficiency of your car while maintaining a constant speed. which i'm not disputing.

what i'm saying is that graph therefore does not apply to an urban (or suburban, or wherever the goalposts are moved to) area.

or are you saying that the most fuel efficient thing to do in an urban area is to try to get to 60mph because that's the peak of your graph?

SeanW

"Urban area" runs the gamut from the kind of places you're probably thinking of (i.e. dense urban cores like Dublin within the canals) to much less dense urban areas e.g. villages etc that do not have the same level of traffic lights and in which people are more likely to be going straight along main roads.

There will also be differences between peak times and off-peak times.

30kph should thus be considered a maneuvering speed limit for places like housing estates and maybe also some dense town/city centres. Apply it inappropriately and you run a risk of adding significantly not just to people's journey times, but also fuel costs.

Flinty997

In the urban setting you're never getting to more fuel efficient speeds for long enough it to make any difference. To do it you'd be accelerating hard to get there and braking hard for the next junction. It's the exact opposite of fuel efficiency. Average speed in Dublin is shockingly low due to congestion.

It's taking cruising speeds for motorways and such and applying them out of all context to the urban setting. It's nonsense. It's especially nonsense for an ICE vehicle.

magicbastarder

going by SeanW's own graph, i suspect he's exaggerating the supposed falloff in fuel efficiency anyway. i've drawn two lines on it corresponding to 20mph and 30mph and the difference in fuel efficiency; one seems to be about 26mpg and the other 28mpg.

his use of 'cliff' is clearly precipitous (boom boom!)

SeanW

https://www.boards.ie/discussion/comment/121152860#Comment_121152860

Again, your argument assumes that journeys involving an urban area are ONLY at peak times and ONLY in the densest urban cores (e.g. Dublin City Centre).

https://www.boards.ie/discussion/comment/121153456#Comment_121153456

We can split hairs about numbers, but the fact is it's less efficient if you are capable of holding a speed for any length of time. Which you very much can do if you travel off-peak and/or outside of Dublin City Centre. And so a blanket 30kph policy needs to be justified as it wastes not just people's time, but also fuel. Given that there are more than 300,000,000 vehicle kilometres between fatalities of any cause - which as you correctly pointed out accrue mainly to people in motor vehicles - and the vast majority of Ireland's 2.5/2.8 million drivers will never even be involved in, let alone the cause of a fatal incident, that justification for such deep cuts is a stretch at best.

Flinty997

Peak times doesn't change the distance between lights and junctions. You ain't "cruising" at fuel efficient speeds in the urban environment. End of. It's not just about fatalities. That's another misdirection.

SeanW

Again, not all "urban environment" roads are the same. In many cases you can easily cruise for 500m - 2km. And even when there are traffic lights they are often green.

magicbastarder

he keeps talking as if he knows what the optimum speed is in stop/start traffic, for fuel efficiency. i've yet to see him quote anything to support that.

this much is clear - even if 80km/h is the ideal speed to maintain on an open road, in terms of fuel efficiency; it's not going to be that in urban or suburban traffic. the optimum speed will be lower than that (and will probably vary with conditions anyway). what it is; i don't know. but SeanW does not know either. the graph he supplied showed an i think 7.5% difference in fuel economy, when you compare ~30km/h with ~50km/h. a difference which would be dwarfed by being caught at lights a few times, probably.

and lest he mention villages vs an urban environment again; travelling 2km across a 'village' - which would be a damn big village - at 30km/h would be a theoretical max difference of about one and a half minutes compared to doing it at 50km/h. in reality, the difference would be lower. a quick check shows dunboyne is roughly 2km from east to west. is asking people to take a whole extra minute driving that 2km across dunboyne such a big thing?

magicbastarder

just as a random example - the N2 northbound between the canal and the M50; it's a 5km stretch (and in no way in danger of being reduced to 30km/h AFAIK). it'd have long stretches between lights compared to the vast majority of roads in dublin, but has 15 sets of lights in that 5km, or a set every 330m or so. and that'd be considered an 'open' road in an urban environment.

or the R108 from the canal to the M50 (i.e. via ballymun) - 25 sets of lights in 5km. that's a set of lights every 200m.

Flinty997

"...Only a quarter of the 15,600 motorists polled by AA Motor Insurance said they have never broken a red light and just 49.3% said they slow down when approaching an amber light...."

I think we can read between the lines about why all lights are "green".

SeanW

@magicbastarder I never said anything about start-stop traffic. Rather that not every journey in an urban area is subject to start-stop traffic owing to time of day and the density of the area. And yes, there are long straight stretches of road subject to urban limits, which I've pointed out before. It's 2km between Chapelizod and Islandbridge on the R109 in Dublin, for example, and a similar distance between the last junction/lights on the N59 in Galway and the end of urban limits. These are just some examples.

Start wallpapering the place with 30kph limits and everyone who uses those routes is going to have to waste time and fuel crawling for no reason.

@Flinty997 as to the "it's not just about fatalities" your side talks about fatalities endlessly. Like that one who was going on about how "motorists were killing 2 or 3 people every week on our roads" without explaining which of Ireland's 2.5/2.8 million drivers he was accusing, or otherwise how he justified such broad terminology. Or propaganda on the matter from the likes of DaCor referencing the likelihood of bad things happening at various speeds, if your side is going to make the fatalities argument - and your side does so as a matter of routine - practical evidence is relevant.

And I have no idea what you're on about with the "all lights are "green"" line but if you're accusing me of running red lights-

• You're wrong, and,
• I wonder if you're not throwing the proverbial stones from a proverbial glass house.