Netherlands' National Wildlife Crossing Network — Meerjarenprogramma Ontsnippering (MJPO)

Starting with badger tunnels built in 1974 and the first large green bridges over the A50 motorway in 1988, the Netherlands built one of the world's most extensive wildlife-crossing networks under Rijkswaterstaat and ProRail, the national roads and rail agencies. The Multi-Year Programme for Defragmentation (MJPO), run 2005-2018, targeted 176 official ecological barriers where roads, railways and waterways cut through the National Ecological Network.

The programme built ecoducts, eco-culverts, wildlife underpasses, tree-crown-level overpasses and adapted bridges across the national road, rail and waterway network.

By the end of 2018, 126 barriers were fully removed and 40 more partially addressed; the country's road network now carries more than 2,100 dedicated wildlife crossings. A peer-reviewed evaluation (van der Grift et al., Landscape Ecology, 2020) found that about 62% of target species use ecoducts as intended and that fenced crossing structures cut large-mammal roadkill by roughly 83%. The programme raised an estimated 1,734 T-EQA of threat-weighted ecological quality at a total cost of about EUR 283 million.

The same study found ecoducts to be the most expensive mitigation type per unit of ecological gain - large fauna tunnels and shared-use viaducts were more cost-effective, and buying and restoring agricultural land outperformed building new crossings on pure cost-effectiveness grounds. Researchers and the Dutch government treat this as an argument for mixing cheaper measures with ecoducts rather than a case against the network, which remains a reference model cited across Europe.