These spaces are as much a part of the interchange zone design overall as its built elements. Their quality therefore needs to be evaluated in a similar manner.
Disproportionately large, empty interchange zone spaces can make passengers feel threatened, especially late at night or early in the morning. The spatial proportion is important to ensure that passengers feel comfortable, secure and do not feel ill at ease or threatened, while at the same time it must be able to cope with maximum capacities.
For example, narrow but high-ceilinged spaces, or wide but low-ceilinged spaces may have the appropriate capacity for their usage, but feel cramped or threatening. Equally, a wide-open, undefined space may be disorientating.
Consideration should be given at design stage to current as well as future capacity demands on the interchange.
Most spaces within interchange zones will be defined by the nature and degree of enclosure. The interchange zone must feel open while not feeling desolate and empty.
Clear sightlines are important, to promote a feeling of security. Opportunity spaces where retail and catering facilities are provided are ideal as their frontages will generate activity and provide enclosure. Enclosure is also sometimes appropriate, for example at waiting areas along platforms exposed to the wind, rain and cold.
See also Protected environment.
Attractive frontages of commercial space lining the corridors and zones of the interchange zone can be an asset; active frontages can provide life to the interchange zone and links between internal and open spaces.
Care must be taken to ensure that the main use of the location as an interchange facility is not camouflaged by untidy or excessive amounts of retail frontage.
In this context, this refers to the relationship between spaces within the interchange zone and facilities or adjacent buildings and the functions of both. For example, do opportunity spaces within the interchange zone also provide access to/from retail facilities? If so, has interaction between these functions been designed to be compatible and complementary, without conflict?
See also Permeability.