Strategic projects PEMB

Urban integration of the B-23 and connection with the Diagonal

  • Mobility and accessibility
  • 2015
  • Developing
  • Operating
  • Stand-by

This extension of the Diagonal of Barcelona, in its concept as an urban avenue, will allow the integration of the road infrastructure in the different municipalities through which it passes and that, today, are practically divided in two by the passage of this roadway.

Project Leader

Xavier Segura i Grau, director of Services of the Public Space of the Metropolitan Area of Barcelona


  • Integration of the road infrastructure of the B-23 with the urban fabric of the municipalities that it crosses, from the junction with the B-20 (Ronda de Dalt), in the municipal district of Sant Joan Despí, to the Parc Riu Llobregat.
  • Improvement of connectivity in all modes of sustainable transport.


The studies propose the transformation of the B-23 into a civic route, which would allow recovery of the urban relations that the motorway severs over the course of the 5 km that run from the Parc Cervantes in Barcelona, to the Avinguda Llobregat at Sant Joan Despí. This transformation will allow the extension of Diagonal de Barcelona in the municipal districts of Esplugues, Sant Just Desvern and Sant Joan Despí up to the River Llobregat.

The urban development proposal means maintaining the B-23 as a segregated route with its current road capacity, but transforming its section to convert it into a civic route that prolongs the Avinguda Diagonal incorporating public transport systems and routes for pedestrians and bicycles, which link Barcelona with the Llobregat. The construction of lateral carriageways on both sides of the B-23 and the redesigning of the section must permit maximum connectivity, both along the length of the route and between the two parts of the “city” which are currently segregated.

The overall transformation of all the pavements is proposed with the most appropriate solutions for each section according to the different characteristics of the sections of urban fabric crossed. The transformation has constant unitary characteristics but also contemplates the possibility of incorporating individualised solutions suitable for the problems of each section, with covering and burying at certain points where required.

The current study is the starting point of the future project, after analysing different proposals for transformation.

On 19 March 2015, the signing of the collaboration protocol between the councils of Barcelona, Esplugues de Llobregat, Sant Joan Despí and Sant Just Desvern and the AMB took place, for the drawing up of the studies of accessibility and urban integration of the B-23. And during 2015 the mobility studies linked to the area affected by the proposal will be undertaken.


  • Global length of the stretch affected: 5 km.
  • Area of urban development of the new side roads:
    • Northern side road: 212,575.0 m2.
    • Southern side road: 170,000.0 m2.
  • Areas of urban transformation: 122,600.0 m2

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