In recent decades, underground usage in urban areas has expanded from subways and utilities to include virtually every non-residential building function. Greater usage of underground space is envisioned in the more congested urban areas in the world such as Asia and Europe. This increasing interest in underground development is raising basic questions about whether people can work and live underground, and if so, what design techniques can sucessfully be employed. The actual experience of people in underground space, as well as general associations and image of the underground reveal predominantly negative attitudes. A number of design techniques have been suggested by researchers, or actually utilized by designers, to alleviate these potential problems for people in underground space. This paper identifies these psychological and physiological problems. In addition, design objective and possible solutions are briefly summarized. This is followed by a summary of special design problems and objectives related to road tunnels.