Filtered permeability on Limerick’s South Circular Road is only option which complies with amendment and project goals

Comment & Analysis: Yesterday, after much checking and going over what was said at the Limerick metropolitan area council meeting in the morning, I published a news article titled: “Limerick councillors vote to replace section of cycle path with filtered permeability“. I’ve received some criticism of this article and even the idea that a filter could work.

Like some councillors, I’ll say first that filtered permeability at this location isn’t my idea, it was drawn up as an option developed out of the workshops with councillors and officials.'s reader-funded journalism won't survive without your help. With over 762,000 views so-far this year, it's not just "avid cyclists" who read this website, but, if you want it to keep going, more support is needed from readers like you. Now, back to the article...

The last article included the text of the amendment which was read out at the council meeting by its proposer Cllr Daniel Butler (FG) — which refers to a “permeability measure” to allow local traffic only, and a shared surface between Summerville Ave and Laurel Hill Ave with the reinstatement of parking.

This is the amendment as read out by Cllr Butler:

“It’s very clear. We propose the removal of the permeability filter north of Lifford Ave/South Circular Road, the introduction of a permeability measure at South Circular Road / Ballinacurra Road junction — exactly the same as your’s, there’s not much difference here, the introduction of a permeability measure north of Ashbourne Ave / New Street junction to allow local traffic only, introduction of a permeability measure the north of the South Circular Road / Summerville Ave to allow local traffic only, introduction of a shared surface between Summerville Ave and Laurel Hill Ave with the reinstatement of car parking. It’s very clear.”

It’s been said to me since that Cllr Butler has referred to “modification 1” on Twitter. But it wasn’t named in the motion, and on Live95 FM, a local station in Limerick, Cllr Butler this morning said officials have “a number of options”.

And Cllr Dan McSweeney said at yesterday’s meeting that officials have “flexibility” in terms of the detail — this is something he confirmed to me when talking to me on the phone yesterday that this “flexibility” is about the design of the filter locations.

As others have said, just putting up signs saying residents only / access only isn’t going to wash and shouldn’t be funded.

So, the only realistic option which will comply with the amendment is “modification 2”, with parking, is basically bollards across the top of the junction at Summerville Ave:

Zoomed in, this is a low-resolution, but the key elements to this are (1) bollards, which are a “permeability measure”, and (2) a turning area for local traffic:

Between Summerville Ave and Laurel Hill is a small area with a limited number of houses and, so, a limited number of cars.

Areas where through traffic is filtered out are not comparable to what’s currently there — motor traffic goes from a flow of traffic to a trickle… to the point where you can often stand in the road at times while that would have been reckless previously:

VIDEO: Standing in the road on Grangegorman Lower.

There’s at least one recent Irish example of where residents can only go as far as a set of bollards and have to turn back along a confined road with parking — Haverty Road in Marino where residents have to turn back at the bollards. This made the former rat run into a street local access only, ie local access as in the same as what’s said in the amendment for South Circular Road.

IMAGE: A trial permeability measure at Haverty Road in Marino, Dublin.

For when motorists meet each other or cyclists, there are already areas where people can pull in and these can be added to or made more formalised:

IMAGE: South Circular Road as it is now.

The residents who objected to the route could turn around and say we also oppose this but that’s usually the nature of an actual compromise.

Like any of the filters put in Dublin etc such as in Drumcondra, Grangegorman, Ringsend etc, the main benefit is a quieter area. These filters were originally more brash looking like Haverty Road but have been refined:

Filtering out through traffic can transform an area and it really cannot be compared to how the area is now. Here is a clip from Dublin City Council with some residents and parents who bring children to the local school talking about the benefits:

I can understand the scepticism but the effect of a filter in reducing traffic is nearly unimaginable until you see it happen on a street you know. I used to live on Grangegorman Lower and it’s a transformation.

In Limerick, the longer shared surface area of the project is likely to be more problematic that the new share area. This is due to it being longer, having more access points, and only having a limited one-way filter.

None of the alternatives for Summerville Ave to Laurel Hill Ave are workable:

— ‘Local access only’ signs cannot be enforced 24/7.
— No legislation for camera enforcement and widely abused elsewhere.
— Traffic lights only are unlikely to be sufficient or enforceable enough.

Between Summerville Ave to Laurel Hill Ave is a tight squeeze at around 5m wide for the length of around 240m along the street — with a 2.75m min space for motorists outlined, the two-way cycle path was going to be just 2.25m (ie the width which unidirectional cycle paths should be).

IMAGE: Original Part 8 drawings.

So, the filtered permeability and shared surface aren’t replacing any kind of ideal situation.

Cycling campaigners, councillors, and others who want to see Limerick become cycling friendly are right to say filtered permeability might not be a done deal. But I cannot see any other workable alternative without a new Part 8 process or which the NTA should see as fundable.

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