A major proposal backed by Budapest’s District XV could extend Metro Line 4 in both directions, reaching Budaörs in the west and the Fót Auchan area in the north-east. The ambitious plan would also include large park-and-ride facilities, but it still needs detailed studies and support from the government and the capital.

Budapest’s Metro Line 4 could become the backbone of a much larger suburban transport connection under a proposal approved by the District XV council. The concept would extend the line westwards towards the Auchan shopping centre in Budaörs and eastwards through Zugló and Újpalota towards another Auchan site near Fót.

According to Portfolio, the proposed deadline is ambitious: the entire extended line would enter service by 31 December 2035 at the latest. However, the council’s decision is a request to begin preparing the project, not a commitment that construction will go ahead.

Park-and-ride facilities would help keep cars out of Budapest

A key element of the proposal is the construction of large park-and-ride (P+R) and bike-and-ride (B+R) facilities at both ends of the extended line, near the Auchan sites in Budaörs and Fót. The aim is to persuade commuters travelling towards Budapest from the M1/M7 and M3/M2 motorway corridors to switch to public transport before reaching the capital’s busiest roads.

According to the proposal, this could help reduce congestion, air pollution and through-traffic in inner Budapest, while easing pressure on roads in District XV and other residential areas. The extended line would also create stronger links between suburban railways, the metro, trams and buses, potentially making journeys across the wider metropolitan area easier.

m4 metro line budapest
Photo: BKK

Zugló and Újpalota could gain new connections

The eastern extension would provide a high-capacity, step-free connection through areas including Zugló, Thököly Road, Bosnyák Square and Újpalota. The exact route has not yet been settled.

The proposal calls for detailed professional assessments before a final route is selected. These would include passenger-demand modelling, urban planning studies, cost-benefit analysis, environmental assessments and public consultation.

Two possible routes are being considered for the section from the Szentmihályi stop towards Fót. The District XV proposal favours option B, citing the need to protect green spaces.

The council also stresses that the section near Újpalota and the Pólus Centre must be planned and built with strict environmental safeguards. These would include protecting existing natural areas and local ecosystems, as well as restoring affected land and landscaping after construction.

The proposed timetable runs until 2035

The proposal sets out a demanding schedule for preparing and delivering the extension.

  • By 30 June 2027: Complete a preliminary feasibility study covering route options, passenger forecasts, network connections, station and depot requirements, technical needs, environmental impacts, costs, risks and potential funding sources.
  • By 31 December 2028: Complete the permitting documentation for the selected option and begin the necessary regulatory, environmental, construction and railway-authority procedures.
  • In 2029: Conclude implementation and financing agreements between the government, Budapest Municipality and the relevant district and local councils.
  • By the end of 2035: Aim to bring the entire extended line, from the Budaörs Auchan area to the Fót Auchan area, into service.

The document acknowledges that these dates are political targets and cannot override statutory procedures or technical safety requirements.

budapest public transport metro map
The M4 metro line. Photo: BKK

The district cannot decide on the metro alone

Although District XV has approved the proposal, the district council does not have the authority to plan, permit and deliver a metro extension independently. It is asking the government and Budapest Municipality to launch the preparatory work, involving organisations including the Budapest Transport Centre (BKK), Budapest Transport Company (BKV), the Ministry of Construction and Transport, and the local authorities concerned.

The council’s decision does not create an immediate construction obligation or commit the district to a specific level of spending. The project’s cost and financing requirements would only become clearer after the feasibility study and cost estimates are completed.

The district mayor has been asked to send the decision to the prime minister, the construction and transport minister, Budapest’s mayor, the heads of BKK and BKV, and the mayors of Budaörs, Fót, Törökbálint and the relevant Budapest districts. The mayor must also coordinate with the other local authorities and report back to the council within 60 days on responses and progress.

Could European Union funding help pay for it?

The proposal fits with the broader emphasis on rail-based transport and reducing commuter car traffic associated with Transport and Investment Minister Dávid Vitézy’s portfolio. However, financing remains one of the biggest unanswered questions.

Vitézy said in September that EU funds made available to Hungary could support several major transport projects by 2029, including HÉV suburban railway upgrades, an extension of Metro Line 3, suburban rail developments and improvements to regional railway lines.