Ireland is standing at a crossroads. With legally binding commitments to reduce transport emissions by 50% by 2030, the coming decade will determine how liveable, connected and sustainable Irish cities can become. This was the central message delivered by Professor Brian Caulfield, Professor in Transportation at Trinity College Dublin’s School of Engineering, during the latest event in the E3 Balanced Solutions for a Better World webinar series.

Chaired by Geraldine Herbert—columnist, motoring editor with The Sunday Independent, and founder of Wheels for Women, the session explored how major public transport infrastructure projects, including MetroLink, Luas extensions, and DART+, can reshape Irish mobility, improve quality of life, and help the country meet its climate goals.

A System Under Strain

Transport emissions remain one of Ireland’s most stubborn climate challenges. While other sectors have shown progress, road transport emissions have barely declined. Over 70% of all trips nationally are still made by private car, a figure unchanged since 2012 despite investment in public transport and active travel.

Congestion is worsening too. Dublin now ranks among the most congested cities globally, with growing economic and social costs. According to Caulfield, congestion could cost Dublin over €1.5 billion annually by 2040, and similar pressures are emerging in Cork, Galway and Limerick.

The core problem? “Ireland doesn’t just have a transport problem, we have a space problem,” Caulfield argued. With the population projected to exceed 7 million in the coming decades, existing road networks cannot absorb future demand.

Mega Projects for Mega Challenges

To shift Ireland onto a sustainable path, Caulfield emphasised the need for large-scale, high‑capacity projects. These include:

  • MetroLink
  • Luas extensions to Finglas, Lucan and Poolbeg
  • DART+ expansion westward and along the coastal rail corridor
  • Enhanced commuter rail in Cork, Limerick and Galway
  • 16 BusConnects corridors across Dublin

MetroLink alone could transform mobility across the capital. Though often framed as an airport link, the project will place 175,000 people and nearly 250,000 jobs within a 10‑minute walk of a station. It will also serve 127 schools, five hospitals, and three universities, including a station beneath Trinity College’s own campus.

Criticism of the project’s cost persists, but Caulfield stressed that the cost–benefit ratio remains positive, and that the cost of not building the metro is already substantial. “We’re losing around €700,000 per day in unrealised user benefits by not having this line,” he explained.

Why Buses and Cars Alone Cannot Fix Congestion

During the event, Caulfield dismantled a common misconception: that buses or cars, autonomous or otherwise, could carry the capacity required for Ireland’s growing population.

  • One Metro train = five buses = around 200 cars.
  • No road‑based mode can match the capacity of grade‑separated rail.
  • Relying solely on buses would “gridlock the city”, he said.

Herbert echoed this sentiment, noting that while improved bus networks are essential, “you simply can’t bus your way out of Dublin’s congestion crisis.”

Short-Term Disruption, Long-Term Benefits

Both speakers acknowledged the public concern about construction disruption. MetroLink, Luas works and rail upgrades will bring temporary upheaval to city streets. But Caulfield urged a focus on the long-term horizon: “These systems are built for 60 to 100 years. The inconvenience of construction is tiny compared to the decades of mobility, economic growth and cleaner air they deliver.”

Ireland’s experience with the Luas illustrates this. After initial scepticism, the Luas quickly became a victim of its own success, carrying record passenger numbers and prompting capacity upgrades.

“We’ve never regretted investing in public transport,” Caulfield said. “But we have regretted delays.”

Quick Wins: Act Now, Iterate Later

While mega-projects take years to build, both speakers highlighted immediate, practical steps that could ease the crisis:

  • Park-and-ride hubs at motorway junctions
  • Pilot projects for new cycling or bus corridors
  • Real-time public transparency using sensors and open data
  • Better engagement with local businesses, using evidence from pedestrianisation projects that boost footfall

Herbert stressed that Ireland often falls into “paralysis by analysis”, unwilling to try transformative ideas unless they are perfect. “In European cities, they pilot first, refine later, and communicate clearly,” she noted. “We need more of that confidence.”

Electric Vehicles: Necessary but Not Sufficient

The conversation also touched on electric vehicles and the recent softening of the EU’s 2035 ban on new petrol and diesel cars. Herbert warned that policy uncertainty may slow EV adoption, but Caulfield highlighted another challenge: grid capacity in rural Ireland.

EVs will play a role, he said, but “they don’t solve congestion, space constraints, or the need for better connected, healthier cities.”

A New National Mindset

Caulfield concluded with a powerful historical reminder. One hundred years ago, Ireland undertook the Ardnacrusha hydroelectric scheme, a massive, visionary project that reshaped the nation’s future.

“We need that spirit again,” he said. “A national effort across housing, energy, and transport. Not working in silos, but building the infrastructure Ireland needs for the next century.”

Herbert agreed, reminding the audience that more events in the Balanced Solutions for a Better World series would continue exploring practical, cross‑disciplinary solutions to Ireland’s biggest challenges.

The Path Forward

The message from this session was clear: Ireland must build, boldly, quickly, and continuously. The next decade will define whether Irish cities remain congested and car‑dependent, or whether they become more liveable, sustainable and connected.

The infrastructure required is substantial, but so are the rewards: cleaner air, shorter commutes, safer streets, stronger economies, and a more equitable society.

Or as Caulfield put it simply:
“Build it, and they will come.”