3 Policies Regarding CONSERVATION of World Heritage Properties
3.5 Factors affecting properties
3.5.2 Transportation infrastructure
Conservation of cultural and natural heritage is at the core of the Convention. Conservation includes effective and active measures that can be taken by States Parties to ensure the identification, protection, presentation and transmission of heritage.
There is no single definition of conservation in relation to both cultural and natural heritage. However, with regards to cultural heritage ‘all operations designed to understand a property, know its history and meaning, ensure its material safeguard, and, if required, its restoration and enhancement’ could be part of its conservation (Nara Document on Authenticity). Conservation of natural heritage refers to the protection, care, management and maintenance of ecosystems, habitats, wildlife species and populations, within or outside of their natural environments, in order to safeguard the natural conditions for their long-term permanence (IUCN).
The Conservation theme includes policies related to protection, management, monitoring, impact assessments, factors affecting the properties, tourism and sustainable development.
The physical 'footprint' and derived effects of use (includes visitor transportation infrastructure).
Ground transport infrastructure (For example: Roads, Car parks, Railways, including easements). Air transport infrastructure (For example: Airports, Airstrips). Marine transport infrastructure (For example: Harbour & port facilities). Effects arising from use of transportation infrastructure (For example: Effects of vehicle traffic on roadways, Effects of shipping traffic in shipping routes, Effects of air traffic).
Synthesis based on relevant Committee decisions
The World Heritage Committee requests Heritage Impact Assessments and Environmental Impact Assessments of all significant development proposals in the property and of any major transportation infrastructure project, before approval for the schemes is granted and prior to making any decisions that would be difficult to reverse, including definitive location and plans for construction, in order to identify any adverse impacts on the property and ways to mitigate these impacts, and to submit the HIA and the EIA to the World Heritage Centre for review by the Advisory Bodies, in accordance with Paragraph 172 of the Operational Guidelines (based on Case law on decisions on the State of Conservation). 
 See for example Decisions , , , , , , , , , .