Spaces for movement. Bus Station in the Santiago de Compostela Intermodal Station by IDOM

Description of project by IDOM

Location
The Atlantic axis that runs through Galicia from north to south runs through Santiago de Compostela halfway up the slope parallel to the Sar River. To settle the railroad station in the mid-twentieth century, it was necessary to generate a wide esplanade for the railway yard, which made a strong slope towards the city and important landfills towards the fertile plain of the Sar. From that moment on, the railroad tracks limited the growth of the city to the south, constituting a de facto barrier. The layout of the current railroad station responds to the usual models of through stations, in which the passenger building is located parallel to the tracks that are covered with a metal canopy.

Intermodality
The arrival of the high-speed train to the city has been accompanied by the transformation of the current railroad station into an intermodal station that is becoming the central node of public transport in the city and its area of influence, by making available to the user the possibility of combining different modes of public transport (rail and bus) in a fast and efficient way at a point very close to the city center.

Linked to this transformation was the opportunity to overcome the barrier of the tracks that separated the city from the new neighborhoods that have grown to the south and the park of Brañas del Sar, the new green lung of the city. To achieve these objectives, the project of the intermodal station contemplated the execution of a transversal footbridge that, taking advantage of the existing unevenness between Rúa Horreo and Avenida Clara Campoamor, would pass over the train tracks. This footbridge will provide access to the new railroad terminal and the new bus terminal, bridging the existing differences in elevation and guaranteeing quick access to the different means of public transport and from both terminals to the city.

Building on the edge of the city - relationship with the immediate and distant environment
If the new intermodal footbridge has made it possible to overcome the barrier posed by the train tracks, the new bus terminal has contributed to reconfiguring the urban edge bordering the Sar valley. This boundary condition is linked to the possibility of transforming the building into a viewpoint over its immediate surroundings, the Brañas and the Collegiate Church of Sar, as well as its distant surroundings, the City of Culture. From here it only remains to arrange the elements that we have at our disposal. The structure is concentrated in the central area of the building to avoid interference with the docks, facilitating the movement of vehicles and people. On both sides, there are two large overhangs that cover the docks from the inclement weather.

This same geometry is reproduced in the covering of the upper floor, but on this occasion the upper plane is inclined to help adapt its scale to the different characteristics of its surroundings, a greater height toward the beaches of tracks and platforms, a more controlled volume towards the edge of the city and the park, protecting the waiting and living spaces. This change of scale also allows differentiating the uses that are arranged on both sides of the lobby. To the south, a large terrace opens onto the cafeteria, which is enjoyed by both users and residents of Santiago. To the north, the services are grouped in low bodies that protrude from the glazed perimeter enclosure.

The internal organization of the bus terminal
In contrast to the traditional models of isolated bus stations, where passengers and buses are accessed at the same level and the circulation of one and the other run in parallel, in intermodal stations these circulations are superimposed to facilitate the flow of future users between terminals and between the terminals and the city. This way of organizing the stations internally facilitates access and baggage control.

The bus terminal is organized into two superimposed floors, with the lower floor containing the area of the docks and the roads for vehicle circulation and maneuvering, and the upper floor containing the building that houses the services necessary to serve passengers.

The docks are arranged around a central platform that optimizes the routes for passengers accessing from the upper floor via stairs and elevators located in the central area. On one side of this central platform are lined up the 19 interurban transport docks organized in a herringbone pattern. On the other side, the 6 metropolitan transport bays are arranged in a sawtooth pattern to speed up the movement of buses in and out of the bays, an optimal solution for services with high frequencies and low dwell times.

In addition, the terminal has 11 regulation docks to facilitate the management by the companies of the service periods of the vehicles and in the next phase, it will be possible to implement a parking area for another 11 buses and a service area.

Bus circulation is organized in a clockwise direction as the passenger doors are on the right-hand side. To avoid the crossing of incoming and outgoing movements, the two lanes that connect independently with Avenida Clara Campoamor are separated. On the other hand, the docks have been dimensioned to guarantee accessibility for people with reduced mobility, taking into account the needs of the different platforms integrated into the buses currently on the market.

The upper floor houses the services required by passengers. The accesses and circulations from the walkway and to the docks are clear to facilitate passenger orientation. Thus, everything is in view. The two floors are connected by two vertical communication cores, equipped with mechanical means (elevators, escalators). Their position makes it possible to manage the different types of passengers, with each core being assigned to a passenger flow and allowing orderly passenger traffic.


Bus Station is integrated into the Santiago de Compostela Intermodal Station by IDOM. Photograph by Aitor Ortiz

Sustainability - Passive systems
Controlling natural light.
The large roof plane is pierced by longitudinal skylights that ensure that natural light reaches all interior spaces. In addition, over the uses arranged on the north façade to serve the station users, there is a sliding window that loosens the roof plane, allows visual leaks, and facilitates the introduction of a diffuse light that complements the light from the skylights and the south façade, which is protected from direct sunlight by a large overhang.

By means of these simple mechanisms it is achieved:

- Minimize glare and annoying reflections.
- Avoid excessive light contrasts, since the light comes from several directions and not only from one.
- Achieve high luminosity that is also uniform and suitable for the intended use of circulation and passenger waiting areas.
- Maintain visual contact with the exterior at all times, in a controlled manner.
- Reduce electricity consumption for artificial lighting when outdoor conditions are favorable.

The extension of the roof avoids direct sun radiation inside the terminal, thus avoiding the need to resort to the use of air conditioning systems for many days a year. A biomass boiler is used for heat production to ensure that the parameters for the use of renewable energies, as required by regulations, are met.

Rain protection
The incidence of rain on the first floor has also been analyzed. The central waiting and access area for buses and the bus docks are covered. The most exposed area, open to the southwest winds, is the metropolitan bus docks, which are arranged in a saw-tooth pattern, with the longitudinal arrangement of the buses themselves helping to protect their users from the rain. The structural flight is extended by means of a light structure of metal profiles and ETFE cladding to improve protection from rain for users. As can be seen in the accompanying graph, the final dimension of these overhangs guarantees that the incidence of rain is minimized in the areas of the bus docks where passengers are present.