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# 30kph coming to Dublin road near you? (note warning in post #254)

• Registered Users Posts: 10,378 ✭✭✭✭

Spook_ie wrote: »
About the same as AJR's contribution of 10-20kg bikes vs 1 to 3 tonne vehicles, did you want to ask that question of AJR or just me?

It's all irrelevant!

• Moderators, Society & Culture Moderators, Sports Moderators Posts: 12,465 Mod ✭✭✭✭

Spook_ie wrote: »
Sorry, but if you are involved in a collision as a pedestrian or cyclist with another cyclist then the actual mass of what hits you will make a substantial difference.

10kg bike as base line
75kg rider
Mass increase 650%

2000kg car as base line
75kg driver
Mass increase 3.75%

If you can't see that in an argument of cars v cycles that the mass of the cyclist makes a substantial difference, then you shouldn't be using 10kg v 2000kg as an argument

Wonder why it's always cyclists that seem to think the actual cyclist has no mass or effect during a collision?

Your knowledge of physics seems a bit shaky.

It's the absolute magnitude of the force hitting you that's important, not the relative magnitude of the force. An additional 75kg has the same additional impact whether it's coming via a 10kg bike or a 2000kg car. Calculating percentage differences here is really dumb.

• Registered Users Posts: 2,810 ✭✭✭

Indeed.

According to that calculator,

90 kg (10kg bike+90kg rider) @ 30kph = Av: 1.5kN, Peak: 3kN
90kg (10kg bike+90kg rider) @50kph = Av: 2.5kN, Peak: 5kN

1590kg (1.5 tonne car + 90kg driver) @ 30kph = Av: 26.5kN, Peak: 53kN
1590kg (1.5 tonne car + 90kg driver) @ 50kph = Av: 44.2kN, Peak: 88.3kN

So the force of a 90kg (bike + rider) colliding at 50kph (which excludes every cyclist in Dublin City) turns out to be less than 10% of the impact of a 1.5tonne car colliding at 30kph (which is the safety measure being discussed that is causing such wailing and gnashing of teeth here.

The impact of a 90kg (bike + rider) colliding at 30kph (which still excludes most Dublin City cyclists) is just over 5% of a 1.5 tonne car (+driver) doing the same speed.

@spook.ie, Great calculator, thanks !

• Registered Users Posts: 2,234 ✭✭✭

FarmerBob wrote: »
DCC planning rolling out 30kph to most (all?) main routes in the city.
Can you imagine driving at 30kph on Howth rd, Malahide Rd, Stillorgan Rd, Griffith ave etc. Buses in empty bus lanes sneaking along at 30kph?

https://consultation.dublincity.ie/traffic-and-transport/consultation-proposed-special-speed-limit-2020/

Consultation open until 13 August 2020>>>

https://consultation.dublincity.ie/traffic-and-transport/consultation-proposed-special-speed-limit-2020/consultation/subpage.2016-07-06.7004763650/
Will there be Go safe Vans or Gardai everywhere then?

• Closed Accounts Posts: 1,698 ✭✭✭

bmc58 wrote: »
Will there be Go safe Vans or Gardai everywhere then?

I would guess that there will be sh!t loads of them for the first few weeks, then business as usual thereafter.

Also - nice one for actually getting it back on topic.

• Registered Users Posts: 10,644 ✭✭✭✭

Amirani wrote: »
Your knowledge of physics seems a bit shaky.

It's the absolute magnitude of the force hitting you that's important, not the relative magnitude of the force. An additional 75kg has the same additional impact whether it's coming via a 10kg bike or a 2000kg car. Calculating percentage differences here is really dumb.
Duckjob wrote: »
Indeed.

According to that calculator,

90 kg (10kg bike+90kg rider) @ 30kph = Av: 1.5kN, Peak: 3kN
90kg (10kg bike+90kg rider) @50kph = Av: 2.5kN, Peak: 5kN

1590kg (1.5 tonne car + 90kg driver) @ 30kph = Av: 26.5kN, Peak: 53kN
1590kg (1.5 tonne car + 90kg driver) @ 50kph = Av: 44.2kN, Peak: 88.3kN

So the force of a 90kg (bike + rider) colliding at 50kph (which excludes every cyclist in Dublin City) turns out to be less than 10% of the impact of a 1.5tonne car colliding at 30kph (which is the safety measure being discussed that is causing such wailing and gnashing of teeth here.

The impact of a 90kg (bike + rider) colliding at 30kph (which still excludes most Dublin City cyclists) is just over 5% of a 1.5 tonne car (+driver) doing the same speed.

@spook.ie, Great calculator, thanks !

You all seem to think I'm arguing that a car hitting you isn't as bad, I'm not I'm just trying to make people realise that a 10kg bicycle hitting you is in reality a 10kg plus rider hitting you, a fact that it seems cyclists have difficulty in grasping.

I mean to be honest yeah I'd sooner be hit by a cyclist than a car but in reality I'd rather not be hit by either. So for future reference if you want to argue that a 10kg bike isn't going to hurt you remember it's not a 10kg bike, it's a 10kg plus a cyclist.

• Registered Users Posts: 2,810 ✭✭✭

Spook_ie wrote: »
You all seem to think I'm arguing that a car hitting you isn't as bad, I'm not I'm just trying to make people realise that a 10kg bicycle hitting you is in reality a 10kg plus rider hitting you, a fact that it seems cyclists have difficulty in grasping.

I mean to be honest yeah I'd sooner be hit by a cyclist than a car but in reality I'd rather not be hit by either. So for future reference if you want to argue that a 10kg bike isn't going to hurt you remember it's not a 10kg bike, it's a 10kg plus a cyclist.

Nobody here has a problem grasping that there's a difference between 10kg and 10kg + rider.

I'm just putting it to you, and (others here that are raising questions about bikes being subjected to 30kph limit that whether you count a bike rider
is pointless nitpicking (and irrelevent to the thread topic) when compared with of the figures of a car hitting someone at 30kph (which is directly relevent to the thread topic)

Seriously, sometimes you can salvage some credibility by conceeding that you made a silly point. This is one of those times, fella.

• Registered Users Posts: 10,644 ✭✭✭✭

Duckjob wrote: »
Nobody here has a problem grasping that there's a difference between 10kg and 10kg + rider.

I'm just putting it to you, and (others here that are raising questions about bikes being subjected to 30kph limit that whether you count a bike rider
is pointless nitpicking (and irrelevent to the thread topic) when compared with of the figures of a car hitting someone at 30kph (which is directly relevent to the thread topic)

Seriously, sometimes you can salvage some credibility by conceeding that you made a silly point. This is one of those times, fella.

It's not a silly point, it's a point being made that you can't (as AJR and others often do) mention this magical 10-20kg cycle that if it's involved in an accident won't hurt people, you have to take into account the total mass involved and the mass of the rider is far more than the mass of the bicycle.

• Registered Users Posts: 6,119 ✭✭✭

Spook_ie wrote: »
It's not a silly point, it's a point being made that you can't (as AJR and others often do) mention this magical 10-20kg cycle that if it's involved in an accident won't hurt people, you have to take into account the total mass involved and the mass of the rider is far more than the mass of the bicycle.

Fine, so how difficult is it for a smart but fat lazy slob driving their super light (carbon)fibreglass car to keep to any designated speed limit?

In my opinion, it's easy, and not only that but it's within that smart person's own remit as a road user. Whether it's adhered to or not is only determined by the Gardaí and/or GoSafe. Failure to obey, combined with being caught (however unlikely) is punished.

• Registered Users Posts: 23,042 ✭✭✭✭

Spook_ie wrote: »
It's not a silly point, it's a point being made that you can't (as AJR and others often do) mention this magical 10-20kg cycle that if it's involved in an accident won't hurt people, you have to take into account the total mass involved and the mass of the rider is far more than the mass of the bicycle.

Except that's not what I said, and I'm pretty to sure it's not what anyone said.

What I said was; "Their speeds aren't really comparable, but even if they were, their momentum is in a completely different ballpark. It's the difference between a 10-20kg bike and a 1-3 tonne vehicle."

So you've gone to all that effort finding your momentum calculators to argue against a strawman position that nobody made.

• Registered Users Posts: 8,850 ✭✭✭

The anti-cycling fundamentalists are ruining all the threads on commuting and transport. It's getting to be a joke now. If a law was brought in that made motorists carry a light on their roof they'd want the cyclists sellotape a light to their heads.

Seriously... the speed limit is for the cars that do the damage we hear about every week in the news.

• Moderators, Motoring & Transport Moderators, Regional East Moderators Posts: 6,403 Mod ✭✭✭✭

John_Rambo wrote: »
The anti-cycling fundamentalists are ruining all the threads on commuting and transport. It's getting to be a joke now. If a law was brought in that made motorists carry a light on their roof they'd want the cyclists sellotape a light to their heads.

Seriously... the speed limit is for the cars that do the damage we hear about every week in the news.

It goes both ways, there is a basically a religious war going on, those of us who want to have a balanced discussion end up side lined. I thought most of the incidents in Dublin City were caused by either crappy infrastructure putting different road users into conflict situations, or the absolute blatant traffic light running committed by drivers.

I think everyone's safety would be better served by the installation of red light cameras at every junction, than reducing the planned roads to 30km/h.

• Registered Users Posts: 7,917 ✭✭✭

John_Rambo wrote: »
The anti-cycling fundamentalists are ruining all the threads on commuting and transport. It's getting to be a joke now. If a law was brought in that made motorists carry a light on their roof
Don't give the cyclists ideas, they've actually come up with more ... out there ... ideas though. From another thread.
How about beg buttons for drivers?
Lean out the window and press the button when you want to get through the junction.
We could certainly give automatic overrides to emergency services and maybe buses. Isn't there something already in place to give buses priority at certain traffic lights.

No, not necessary - but it would send a helpful message, wouldn't it?
Most cars are RHD in my experience in Ireland, but sure the LHD drivers can just stop and get out. What's the problem with that?
This same poster has also called for mandatory driver retesting every 5 years, motorists and passengers to be legally required to wear racing helmets while in the car. But, like motorists "beg button" at junctions these are all to do with "road safety" and not a broader motorist-bashing agenda. :rolleyes: (And if you believe that, I have a cycle lane on the Brooklyn Bridge to sell you).

And yet, these people dominate many threads here and Andy seems to be representative of the Irish cycling fraternity, at least if Boards is anything to go by. I suggest that this makes any kind of balanced, reasonable discussion difficult, if not impossible.

• Registered Users Posts: 8,850 ✭✭✭

SeanW wrote: »
And yet, these people dominate many threads here

Yourself and spook_ie are two of the worst antagonisers with this bull. Genuine motorists concerns and experiences are being buried in the thread with your petty, bitchy, childish, long winded, bullsheet threads.

• Registered Users Posts: 20,459 ✭✭✭✭

SeanW wrote:
This same poster has also called for mandatory driver retesting every 5 years, motorists and passengers to be legally required to wear racing helmets while in the car. But, like motorists "beg button" at junctions these are all to do with "road safety" and not a broader motorist-bashing agenda. (And if you believe that, I have a cycle lane on the Brooklyn Bridge to sell you).

You still don't get the irony no matter how many times it's hammered home to you, do you?

"Mandatory testing", "legal requirement to wear racing helmets while commuting", all the typical nonsense we constantly put up with from cyclist-bashers. Funny how the suggestions sound ridiculous when they're turned around?

• Registered Users Posts: 8,850 ✭✭✭

I've felt a bit of pressure on larger roads where 30kph feels like 10kph from drivers behind me. Not that they were tailgating or anything.... just a feeling from their road positioning (slightly over the centre line).

My future fix for this is to pull in and let them by if I have time. Otherwise I'm going to try and trundle along at the speed limit.

• Registered Users Posts: 10,378 ✭✭✭✭

Does this forum not have any mods anymore?

• Registered Users Posts: 13,710 ✭✭✭✭

SeanW wrote: »
This same poster has also called for mandatory driver retesting every 5 years,

That's a good idea. Too many people with no idea how to drive on the road.

Easier idea would be losing your licence for six months once you hit two penalty points.

Bizarre that the system is set up to allow motorists away with so many chances to put innocent lives at risk.

• Closed Accounts Posts: 1,698 ✭✭✭

MJohnston wrote: »
Does this forum not have any mods anymore?

To moderate the massive deviation from the thread topic you mean?

• Registered Users Posts: 7,917 ✭✭✭

Zebra3 wrote: »
That's a good idea. Too many people with no idea how to drive on the road.

Easier idea would be losing your licence for six months once you hit two penalty points.

Bizarre that the system is set up to allow motorists away with so many chances to put innocent lives at risk.
Thank you for making my point so clearly. :rolleyes:

• Registered Users Posts: 10,378 ✭✭✭✭

kenmm wrote: »
To moderate the massive deviation from the thread topic you mean?

Yep!

• Registered Users Posts: 13,710 ✭✭✭✭

SeanW wrote: »
Thank you for making my point so clearly. :rolleyes:

You clearly make your point on here which is basically who cares about all the road deaths, they are lower than in Vietnam so don't do anything else to inconvenience motorists.

• Registered Users Posts: 7,917 ✭✭✭

Actually more like most of the world, including most of Europe. But what you, Andy and the other cyclists demand is more than an "inconvenience," it's downright extreme. And it dominates any discussion on this board, even of threads that did not start out being about motorists.

• Registered Users Posts: 13,710 ✭✭✭✭

SeanW wrote: »
Actually more like most of the world, including most of Europe. But what you, Andy and the other cyclists demand is more than an "inconvenience," it's downright extreme. And it dominates any discussion on this board, even of threads that did not start out being about motorists.

The absolute state of that. :rolleyes:

The only extremism out there on the roads is the absolute domination of motor vehicles.

And your attitude sums it up perfectly.

• Registered Users Posts: 10,378 ✭✭✭✭

Can you two sort this out on the playground instead?

• Closed Accounts Posts: 1,698 ✭✭✭

It's not like the entire thread with all the same arguments and same thread title wasn't done already over on current affairs

• Registered Users Posts: 13,710 ✭✭✭✭

MJohnston wrote: »
Can you two sort this out on the playground instead?

Can't access it, parked car blocking the entrance on the footpath. :pac:

• Moderators, Motoring & Transport Moderators Posts: 13,999 Mod ✭✭✭✭

Back on topic or I’m going straight to infractions followed quickly by bans — most people here have seen enough warnings over the years.

— moderator

• Registered Users Posts: 8,031 ✭✭✭

MJohnston wrote: »
Submitted a strongly supportive response!

I also mentioned the need to back up the lowered speed limits with a drastic, widespread program of road diets, footpath widening, rat run elimination, and lots of other street design measures that will induce motorists to subconsciously reduce their speed. I honestly think that's more important than enforcement, unless the enforcement can be near-omnipresent.

Streets can be redesigned in such a way that it's difficult to drive over 30kph. Example..if vehicles have to weave left and right instead of driveing straight on, results in lower speeds.

Also, narrow streets like this look nice, and are much safer for all:

https://images.app.goo.gl/TFvMdYJn4n1bYqtM8

• Registered Users Posts: 2,810 ✭✭✭

07Lapierre wrote: »
Streets can be redesigned in such a way that it's difficult to drive over 30kph. Example..if vehicles have to weave left and right instead of driveing straight on, results in lower speeds.

Also, narrow streets like this look nice, and are much safer for all:

https://images.app.goo.gl/TFvMdYJn4n1bYqtM8

Our planners unfortunately still seem quite blind to the benefits of adding complexity to streets in built up areas, street furniture, chicanes, raised junctions, noisy paving etc. I think their eyes are opening to be, albeit slowly.

The funny thing is, they dont need to guess and experiment with what actually works. Just copy-and-paste from the Dutch! They are jedis in traffic calming neigbourhoods and making their towns and cities much more pleasant places for a person to be.