At a press conference Wednesday morning, Environment Minister Leonore Gewessler (Greens) announced the cancellation of the highly-contested Lobau Tunnel Construction Project, part of a planned extension to Vienna’s outer ring expressway (S1) that would have passed through the protected Lobau floodplain. The S1 extension aimed to improve traffic flow between parts of the 22nd District and central Vienna—plans which stretch back nearly twenty years and would have cost billions.
The plan was scrapped as a result of a months-long climate impact assessment called for by Gewessler in early July and officially released on Wednesday. The assessment looked into a slew of major road-building projects by highway construction corporation ASFINAG in order to determine their future viability in the face of a changing climate.
The groundbreaking decision marks a win for environmental activists who have been fighting the project for years on the grounds that the project would encourage more people to drive, increasing greenhouse gas emissions, and that it would degrade the Lobau wildlife reserve in Danube-Auen National Park. Activists in the “LobauBleibt” movement have been occupying construction sites in Hirschstetten since late August in an effort to halt progress—a tactic that was used to resist the same project back in 2006.

“Twenty or thirty years from now, our children will ask us: What have you done to save the climate?” said Gewessler at the press conference. “I want to be able to say—we made brave decisions. That’s exactly what the climate check does for the ASFINAG construction program,” she said, noting that the S1 extension would have crossed through a “one-of-a-kind nature reserve” and would have consumed more land than any other project surveyed.
Danube-Auen National Park is home to more than 800 species of plants, 33 mammals, around 100 breeding bird species, 8 reptile and 13 amphibian species, and 67 species of fish. The Lobau Tunnel would have been built 60 meters underneath the floodplain. While ASFINAG environmental assessments argued this would be deep enough to avoid damaging protected areas, twelve members of the group Scientists for Future argued in an August statement that construction could lower the water table in the area, destabilizing the entire ecosystem, destroying protected natural habitats and negatively affecting Vienna’s water supply.

No longer approved
The impact assessment released by Gewessler on Wednesday detailed nearly twenty ASFINAG road construction projects that are planned or underway around the country and reviewed them in light of Austria’s latest climate goals and obligations. New considerations include the protection of “valuable soils, natural spaces and biological diversity,” alongside pre-existing criteria, such as traffic safety, transport network planning, costs, and economic development.
Austria is committed to the Paris Climate Agreement, which aims to limit global heating to +1.5 °C compared to pre-industrial levels—and the country says it will achieve climate neutrality across all sectors by 2040. According to the impact assessment report, these climate targets can only be reached “if there is a radical turnaround of greenhouse gas emissions in the mobility sector.”
The report states that due to the incredibly long planning time for the S1 extension and Lobau Tunnel, which began in 2003, some of the environmental impact assessments were outdated. The project, they said, had been green-lit based on outdated assumptions. For example, the project was justified using some figures and projections from 2011—specifically, public transit fares and Vienna car ownership (both of which have decreased since then), and parking management (parking is more regulated now).
While the S1 extension was meant to relieve traffic congestion and shorten travel time in northeast Vienna, one major finding by traffic experts at TU Wien showed that the Lobau crossing would increase traffic in the long run by encouraging more drivers to use it. According to the report, most traffic relief in the future will result from planned expansions to public transit and better parking space management in the city.
The report also found that past assessments ranked the “con” of increased greenhouse gas emissions as less important than the “pro” of economic growth in the region. According to a 2017 assessment quoted in the report, “No expansion of high-level road traffic infrastructure can have direct positive effects on climate protection.”
In addition to the S1 extension, the planned S34 Traisental expressway and S8 Marchfeld expressway have also been canceled, due to similar concerns of soil loss, land consumption and disturbance of natural areas. The search for alternatives to all three projects has begun, according to the Ministry for Climate Protection. From now on, all major road-building projects will be developed in partnership with the ministry.

Criticism from Mayor Ludwig
Vienna Mayor Michael Ludwig (SPÖ) expressed sharp criticism of Gewessler’s decision during a press conference on Wednesday, saying: “The last word has not yet been spoken” on the Lobau Tunnel project.
“It’s an attack on the quality of life of the Viennese and people in the general eastern region when road projects that have been developed over many years—with the involvement of many experts—are canceled without justification and without a transparent process,” said Ludwig.
Ludwig expressed concern about heavier traffic, more traffic jams and higher emissions from idling cars if the project doesn’t go through—though findings that the S1 extension wouldn’t ultimately reduce traffic are included in the official impact assessment.
Ludwig said the decision would diminish the quality of life in the city and surrounding region, and hinted that legal action from the city may be forthcoming, as lawyers work through the documents and examine next steps.
According to ORF, he also asked what would happen with the planned Stadtstraße extension—the short section of planned highway meant to connect central Vienna to the outer ring. That section of the extension was tied up with housing construction for some 60,000 people. The Stadtstraße extension can still be built as planned, according to the impact report, but Ludwig emphasized that without the Lobau Tunnel, building it no longer makes sense.

Further reactions
As reported by ORF, both the NEOS and Greens political parties in Vienna were pleased about the canceled Lobau Tunnel Construction Project. NEOS representative Bettina Emmerling said in a broadcast: “The most important thing is: now we have clarity. We NEOS welcome the decision, and call on all those involved to act quickly instead of delaying sustainable solutions for years through legal disputes.”
Both the ÖVP and the FPÖ harshly criticized the move, according to ORF. “Today’s decision by Transport Minister Gewessler is absolutely incomprehensible, shows complete irresponsibility and is downright a slap in the face to the Viennese. The decision must be resolutely opposed,” said ÖVP representatives Markus Wölbitsch and Wolfgang Kieslich in a broadcast.
Walter Ruck, President of the Vienna Chamber of Commerce fears billions in damage to the economy, according to ORF. “The Lobau Tunnel is of essential importance for business in Vienna and the eastern region,” said Ruck, pointing to business relocation and new jobs associated with the project’s completion. “No infrastructure project in Austria has been examined so intensively as this tunnel.”
A slate of environmental advocates, by contrast, cheered the project’s end, including Greenpeace, the Austrian Transport Club, activists from the Jugendrat, Fridays For Future, System Change not Climate Change, and Extinction Rebellion, along with environmental organizations Virus, Alliance for Nature, Südwind, WWF, and the Naturschutzbund, reported ORF. Global 2000 stated in a broadcast, “The Lobau expressway is an ancient project from the Stone Age of transport policy. Now, the City of Vienna has the chance to develop future-oriented and climate-friendly solutions.”
Activists from the “LobauBleibt” movement did not let up on the pressure the day of the announcement, demonstrating against the construction of the Stadtstraße extension in front of Vienna City Hall on Wednesday evening.