Swedish design studio Visiondivision has come up with a proposal for a sheltered promenade, outdoor cinema and art gallery for the redundant space within the structure of Stockholm's Tranebergsbron bridge.

Anders Berensson and Ulf Mejergren of Visiondivison developed the Under the Bridge strategy to shorten the time it takes for pedestrians to cross the waters between the city island Kungsholmen and the western suburb of Bromma.

According to the designers, the walk currently takes 15 minutes and involves following a noisy highway. They believe this time could be reduced to just three minutes by adding a new walkway that follows the arch of one of the existing concrete vaults.

"We looked at the bridge as a whole and saw that the beautiful concrete vaults were ideal to make a more rapid connection between the two sides, and that connecting these two hotspots would also allow a much greater potential in creating activities," the designers told Dezeen.

The passageway would pass through a series of pre-existing doorways in the concrete pillars that support the bridge. The main construction needed would be the addition of stairs on the vault, new lighting and balustrades.

"Since it is relatively cheap to build and will have a huge effect on the site, we really hope to see this realised," added Berensson and Mejergren.

The designers suggest that the huge concrete pillars could also be used as projection walls for occasional movie screenings, or could function as exhibition spaces for hanging artwork.

Red concrete paving tiles would be added to encourage people to follow the path, and small kiosks could be set up in the abutments.

Here's a project description from Visiondivision:

Under the Bridge

Stockholm's many islands has created a beautiful city to live in but it has also created barriers between the inner city and the suburbs. Large scale bridges connects many of these places to each other, often built with the car in mind.

Tranebergsbron is one of the most beautiful bridges in Stockholm and connects the city island Kungsholmen with the western suburbs. It was completed in 1934, at that time having the world's largest bridge vaults in concrete.

In 2005 an identical bridge vault was added to the two original ones, allowing more cars on the bridge. As many bridges that is predominantly built for cars, the construction begins to incline many hundreds of metres on land on both sides the shore, this means that if you want to walk over the bridge it will involve a strenuous 15 minute walk in a noisy environment considering that you will walk just next to a busy highway.

We therefore propose to use the actual concrete vault of the recently built bridge to cater to the neglected pedestrian traffic between these two important areas in Stockholm and to dramatically shorten the time between the two shores and make the journey into a pleasant three minute walk in a beautiful and relaxed setting. To do this, only a minimal intervention is required.

The concrete pillars that connects the vault with the surface of the bridge already has holes in them, so the only thing that is necessary to do is to extend the upper part of the vault to allow passage and to add stairs on to the vault, proper lighting and a protective fence. The ground before the arc begins could also be treated with red concrete tiles to highlight the new path better and make it more accessible.

The two shores would benefit tremendously from being better connected to each other and they are both major gateways that are currently undergoing a great expansion with new housing and services.

With the underworld of the bridge suddenly being used, this would also mean that the beautiful space underneath the bridge will be better activated, which leaves room for new functions and ideas. The impressive concrete pillars would be perfect to use as a temporary art gallery and the stairs on the vaults can have a double use as seating to watch film screenings on the pillars.

The two abutments would be attractive spots where small kiosks could be set up when weather permits.