N17 - Knock to Collooney [design & planning underway]

The preferred corridor will be published on www.n17knockcollooney.ie on the 31st of January 2023. According to a Sligo Co Co press release today.

2045 was the initial date of completion so i'd say 2047!

Landowners have begun receiving letters now so not long to wait thankfully!!

Are you suggesting that the new road will be SC?

Yes I think so. The N17 along this stretch has AADT of 6k or 7k, which is actually in the range for a type 2 single carriageway (<8,600 AADT). There's no way they would make it type 2 single as the rest of the N17 is wide SC. Type 1 SC is OK for AADT of up to 11,600, so that should cover the N17 for the next few decades at least. They will hopefully try to come up with a justification for T2 dual (such as better safety record etc), but it would be hard to get it approved given that major road projects are subjected to more rigorous scrutiny these days based on their environmental impact. I'd say that's why they dropped the section south of Knock Airport, and kept the new preferred route mostly very close to the existing N17.

Type 1 Single with a limited number of (maybe compact-GSJ) junctions will do just fine here - as @DumbBrunette says the traffic levels are very low, and safety, not capacity is the driving force behind the upgrade. If traffic does increase in future, it’s not very expensive to widen to 2+2 so long as any structures over are made wide enough (which I believe now have to be on all new primary Single Carriageway builds).

The junction with N5 seems a little wasteful when there’s already a new overbridge just a couple of hundred metres to the west.

The Tobercurry and Charlestown bypasses are the most justifiable sections of this project and align with government policies regarding making town centres more attractive, focusing development around existing settlements, etc.

Looking at the route, I think it would be better to reduce the scope of the project to south of Charlestown to north Tobercurry (basically the green and red sections). I think the Business Case for this would be much stronger and would be more likely to actually happen. The rest could be done as smaller online upgrades with short offline sections where necessary. I'd still be looking at 4 or 5km offline new build around Ballynacarrow though.

The Connacht Telegraph is saying it will be the 2030s until construction starts.

This is one of the issues with these massive planning undertakings, everything is wrapped up together but nothing can happen until the entire thing has run its course. That's 30km between Charlestown and Coolaney on ice for several years.

He highlighted that the dangerous junctions on the section between the airport and Knock also need to be addressed, and that could be done now.

I thought that part of the above linked article was interesting. There must be an intention to do works around the airport separately, which pressumably is why it is not really part of the scope. I think this approach should be taken on other sections too.

Even though the current traffic patterns may not justify a DC on this route, my hope would be that they build for the future. Our population will grow, Sligo and its hinterland will grow given the huge demand for housing. With not even a mention in the rail review of them reinstating the line from Galway up to Sligo, joining two population centres, which would probably make the thing somewhat viable, the road is the only show in town it seems. The traffic levels may not justify it right now, but in the coming years I'm sure it will.