N4 to Dublin

liam7831

Seems pretty f**cked every morning now and will only get worse

L1011

Ramp metering at Celbridge is the only thing that could help in the short term. It'll be widened to 3 lanes to Kilcock in a few years but then the capacity isn't there further in

More peak rail capacity is years off, there will be some extra bus capacity come New Year but not much

pad199207

liam7831 wrote: »

Seems pretty f**cked every morning now and will only get worse

Be thankful you dont have to do the N7

Joe Public

L1011 wrote: »

Ramp metering at Celbridge is the only thing that could help in the short term.

Please explain

L1011

Chaotic merging eastbound at Celbridge is the #1 cause of delays further back. Ramp metering is where you only allow a certain amount of traffic on. Usually it ends up being that the same amount is let on, just in a sensible manner to prevent the mainline stopping.

It is available but rarely used at Coolock Lane on the old M1, not sure if there are other setups.

Joe Public

L1011 wrote: »

Chaotic merging eastbound at Celbridge is the #1 cause of delays further back. Ramp metering is where you only allow a certain amount of traffic on. Usually it ends up being that the same amount is let on, just in a sensible manner to prevent the mainline stopping.

It is available but rarely used at Coolock Lane on the old M1, not sure if there are other setups.

I've never gone that way in the mornings but always see that traffic is usually back as far as the Spa Hotel and this morning it was back much further due to one lane being blocked opposite the hotel. If the main M4 traffic got through quicker at the Celbridge/Leixlip on ramp it's still going to crawl from the Spa Hotel or further back.
I often merge on the N7 at Newcastle where there is a barrier running for about 200m which prevents early merging, is this the kind of solution you mean?

Probably worth doing a video of how the traffic typically merges from the Celbridge/Leixlip ramp some morning.

ixus

Used to be able to hit the motorway at 6.50 and be anywhere in 30 London M50 radius. Even in 2006 at the peak. Now you hit traffic instantly upon entering m4

L1011

Joe Public wrote: »

I've never gone that way in the mornings but always see that traffic is usually back as far as the Spa Hotel and this morning it was back much further due to one lane being blocked opposite the hotel. If the main M4 traffic got through quicker at the Celbridge/Leixlip on ramp it's still going to crawl from the Spa Hotel or further back.
I often merge on the N7 at Newcastle where there is a barrier running for about 200m which prevents early merging, is this the kind of solution you mean?

Probably worth doing a video of how the traffic typically merges from the Celbridge/Leixlip ramp some morning.

No, its actually traffic lights to limit how many join in one go

https://en.wikipedia.org/wiki/Ramp_meter

mloc123

Ramp metering will not solve the issue... the problem is we are funnelling too many cars in a city centre that was designed(?) hundreds of years ago and not suitable for the volume.

L1011

mloc123 wrote: »

Ramp metering will not solve the issue... the problem is we are funnelling too many cars in a city centre that was designed(?) hundreds of years ago and not suitable for the volume.

It'll fix one element of it - it's still going to run out of capacity closer in as I said anyway.

The city centre has a mix of medieval street layout and widened late 18th century ones (which is why there's so few very old buildings in the centre); unfortunately the wider streets is probably why we have so many cars in the centre - many similar age cities have vastly smaller roads so put proper effort in to getting cars out decades ago.