Trevor Laffan: Major flaw in €215m Dunkettle project that means jams today

I’m a little confused, which isn’t all that strange. I don’t have an engineering degree either, which probably s for some of it. Maybe I’m missing the bigger picture, but I need to get this off my chest so prepare yourself for a rant.

I drove my wife to the Mater Hospital in Mahon recently for an 8.30am appointment. We left Cobh at 7.30am because my wife was anxious about being late, despite my reassurances that we had loads of time.

The new Dunkettle Interchange was fully operational so we should easily make it. My confidence was misplaced though.

When we reached Cobh Cross, I noticed traffic was slowing on the N25 heading west. It’s been a while since I was on the road at that hour of the morning so I’m no longer familiar with the normal traffic volume at rush hour. I was surprised though to find myself crawling along at a snail’s pace before I even hit the N25.

I suspected there was an accident up ahead, but thankfully the traffic soon began to move again, and we were on our way.

Both lanes were full heading towards the city, and we were making decent progress until we hit the slip road for the tunnel. At that point, the two lanes came to a halt and we began a stop-start movement.

Further along the road, we were ed from the left by the traffic coming from Little Island, which meant we now had three lanes merging into two. At the same time, the traffic in the lane to my right was being forced into my lane, so now we had three lanes merging into one and we’re all heading for the tunnel.

At the entrance to the tunnel, we were ed by the traffic coming from the Dublin direction, so we were back to two lanes again. But there are only two lanes going west in the Jack Lynch Tunnel, so the N8 traffic uses the right-hand lane and the traffic heading west on the N25 use the left lane.

So, basically, all the traffic coming from the east that wants to head west is making its way towards a bottleneck and a single lane in the tunnel.

And this surprised me because I was expecting something better.

To my non-engineering brain, it seems badly designed, and as far as I can see, it’s only going to get worse. Where you have a huge volume of traffic being forced to merge into a bottleneck, it is never going to flow smoothly.

I heard someone commenting that the new interchange design layout works well during normal traffic, but it can be slow when the volume is high. I thought the whole purpose of a freeway was to make sure that heavy traffic could flow freely all the time.

Every system will work fine when traffic is light!

A freeway, as the name suggests, is designed to keep the traffic moving freely without obstructions such as traffic lights and roundabouts, but the current Dunkettle Interchange is not achieving that.

It never will either unless a third bore is added to the tunnel, which, I suspect, is out of the question, or a flyover is added to the mix, which is probably unlikely too.

So, is this interchange the great feat of engineering it was proclaimed to be at the official opening?

Irish Building Magazine said at the time that the Dunkettle Interchange Upgrade Scheme marked a significant milestone in enhancing transportation infrastructure and connectivity in Cork.

The €215m project promised to alleviate congestion, improve safety, and streamline traffic flow for the region’s residents and businesses.

Traffic volumes through the Dunkettle Interchange were approaching 120,000 vehicles on the busier days of the week.

Despite this, Irish Building Magazine reported that journey times during peak hours had reduced by almost 50% on average as a result of this upgrade project.

The then Lord Mayor of Cork, Cllr Kieran McCarthy said: “The new Interchange stands as an important additional piece in the strategic transport infrastructure in metropolitan Cork.

“The new interchange is also an engineering feat and adds to the adjacent tunnel’s story and narratives,” he said.

“In our time, the removal of critical bottle-necks creates better traffic flows but also greater connectivity between communities on either side of the River Lee’s estuary.

“The enhanced connectivity facilitated by this project will undoubtedly fuel progress.”

At the official launch of the project, then Taoiseach Micheál Martin said of the upgrade: “It’s a very significant project, an important one in of the modern infrastructure around Cork in of facilitating traffic, but also releasing the potential for significant housebuilding as well, so we can get more homes for people in communities and for couples who are looking for them.”

On completion of the construction, Mr Martin, then Tánaiste, described the upgrade as an “extraordinary engineering achievement. This will make a huge difference when it comes to business, tourism, public transport, and road safety in Cork”.

I’m not so sure about it being such a feat of engineering because it’s already struggling to cope with the current volume of traffic, and it’s only going to get more congested.

Plans are afoot to deal with two other bottlenecks on the N25, in Killeagh and in Castlemartyr both of which have been holding up traffic for years.

Once they’re freed up, traffic flowing from east to west on the N25 will make better headway and should get to the slip road for the Jack Lynch Tunnel more quickly, only to the queue which is already forming at the new bottleneck.

It took ten years and €215m to deliver this project and I was hoping for something better.

Maybe I should learn to manage my expectations.