The first High-level Meeting on Transport, Health and Environment was convened by the UNECE and WHO/Europe secretariat on 4 May 2001 to decide on further steps for achieving transport sustainable for health and the environment at the pan-European level. The Meeting decided, among other things, to rationalize the work on transport, health and environment carried out by UNECE and WHO/Europe under the Vienna (Regional Conference on Transport and the Environment, 12-14 November 1997) and London (third Ministerial Conference on Environment and Health, 16-18 June 1999) follow-up processes, through consolidation of the international institutional mechanisms and prioritization of the related work.
The second High-level Meeting, held on 5 July 2002, established THE PEP for joint administration under the auspices of UNECE and WHO/Europe. In particular, it decided on THE PEP Policy Framework, THE PEP work plan and the establishment of THE PEP Steering Committee.
The third High-level Meeting was held on 22-23 January 2009 in Amsterdam, adopting the Amsterdam Declaration and THE PEP Work Plan (2009-2014).
The fourth High-level Meeting was held from 14 to 16 April 2014 in Paris, adopting the Paris Declaration and THE PEP Work Plan (2014-2020).
The fifth High-level Meeting was held in Vienna from 17 to 18 May 2021, adopting the Vienna Declaration and THE PEP Workplan (2021-2025).