Barcelona’s City Council has approved key urban planning projects to complete the long-awaited tram connection along Avinguda Diagonal. This decision clears a major administrative hurdle, linking the city’s two disconnected tram networks between Plaça de Mossèn Jacint Verdaguer and Plaça de Francesc Macià.

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On Tuesday, the council’s Ecology, Urbanism, Mobility, and Housing Commission approved executive projects for the avenue’s comprehensive reurbanisation and the installation of a new, larger water collector system beneath it. This marks a significant step towards unifying the Trambaix and Trambesòs lines, a project debated for over two decades.

A Three-Phase Project

The ambitious plan is divided into three distinct parts. The first involves installing a high-capacity water collector between Carrer de Girona and Francesc Macià to mitigate the risk of flooding. The second, now approved, is the complete overhaul of the avenue’s surface to accommodate the new tram platform. The final stage will be the installation of the tracks and catenary system itself.

The total estimated cost is €195 million. The City Council will contribute over €115 million, covering €62 million for the water collector and €53 million for the reurbanisation. The Generalitat de Catalunya, via the Metropolitan Transport Authority (ATM), will fund the remaining €80 million for the tram infrastructure.

With Tuesday’s approval, Mayor Jaume Collboni‘s administration anticipates the ATM will grant final approval for the tram infrastructure project in April. However, officials caution that works, projected to last 40 months, can only begin once the city and regional government sign a formal financing agreement.

Political Division and Budgetary Hurdles

The project’s approval highlighted the city’s political fault lines. The reurbanisation plan passed with the support of the governing Socialist party (PSC), along with BComú and ERC. Junts, PP, and Vox voted against it. The essential water collector project, however, received broad consensus, with only Vox abstaining.

First Deputy Mayor Laia Bonet described the plan as a “strategic transformation” for a “more sustainable and better-connected” Barcelona. She stressed that a project of this scale “requires institutional agreement and political commitment,” directly referencing the need for budgetary allocations. As Barna.News has previously reported, the entire Diagonal tram plan hinges on the Catalan budget passing in the Generalitat.

Speaking at an event at the DFactory innovation hub, Mayor Collboni said the connection would encourage “117,000 residents of Barcelona and the Metropolitan Area to use this transport of the future more often.”

A Greener, More Accessible Avenue

The transformation will cover a nearly three-kilometre stretch of the iconic avenue, reimagining it in a similar style to the recently completed section between Glòries and Verdaguer. The redesign will add 16,000 square metres of pedestrian space and create almost 19,000 square metres of new green areas.

Cyclists will also benefit from an additional 1,800 square metres of dedicated space, part of a wider effort to improve cycling infrastructure, which includes the new Diagonal bike lane connecting to Esplugues. The project is one of several major redevelopments reshaping key city arteries, alongside the final phase of works on Balmes Street.

Three new tram stops are planned: Diagonal | Cinc d’Oros, Balmes, and Casanova.

Cross-Party Reactions

While BComú voted in favour, councillor Guille López criticised the current government’s pace. “This is a lost term for the tram,” he stated, arguing the project should have been pushed through at the start of the mandate. He called the delay “negligent,” especially given the ongoing service issues on the Rodalies commuter train network.

Rosa Suriñach of ERC justified her party’s support by citing the expansion of public transport, the improvement of a key public space, and the increased climate resilience from the new water collector. In a pointed remark aimed at the Socialists, she noted that securing support for the Generalitat’s budget required “fulfilling agreements.”

Conversely, representatives from PP and Vox dismissed the project as a “political decision” and an “ideological experiment,” respectively, arguing it fails to address the city’s fundamental mobility problems.

With administrative approvals now secured, the focus shifts to political and financial negotiations between the city and the Generalitat. Only once these are resolved can the 40-month countdown to a fully connected tram network truly begin.