Dr Alain L’Hostis (M) is research director at Université Gustave Eiffel. Holding a PhD (U Tours) and a habilitation (U Paris-Est Marne la Vallée) in spatial planning. He develops a research programme on geographical distances. On interuban distances he develops a theoretical approach on time-space representation. This programme also contains reflections and developments on the concept of accessibility. On urban distances the research focuses on the operational and theoretical urbanism model of Transit Oriented Development (TOD). He has been involved in a dozen of international research projects as partner (CLOSER. MOBILITY4EU) or as leader (BahnVille2, CISMOP).