In cities across the globe, changing technologies and ways of travelling and working are leading to abandoned and obsolete public infrastructure. Railway lines, roads, waterways, ports, underground stations and more lie empty and abandoned.

Meanwhile, we are running out of space in our towns and cities to develop new parks and leisure spaces. And of course there’s an urgent need to design and build in a more sustainable way. It’s essential we reuse existing materials and structures as much as we can, rather than dismantling them and sending their components to landfill.

These factors are leading to a range of imaginative projects that see old infrastructure used in new and surprising ways.

We all know about the High Line and the way it has transformed New York, of course. While it’s probably the best known example of the adaptive reuse of infrastructure, there are many other incredible projects taking shape across the world.

On p76, we interview Alice Shay. Shay works within BuroHappold’s Cities Practice team, and leads the firm’s work on ‘stranded assets’ projects.

In New York, BuroHappold is working with the New York State Canal Corporation and New York Power Authority to imagine a new future for the Erie Canal. Once a key generator of wealth for Upstate New York, it now has huge potential for tourism and recreational use.

A competition resulted in shortlisted proposals that are currently being explored, including freezing part of the canal to be used as a skating rink in winter, running a brewing festival to celebrate the heritage of the region and attract people to the area, and the development of a canalside pocket neighbourhood.

Meanwhile, James Ramsey and Dan Barasch’s Lowline project is taking shape in New York; they are using innovative technology in the shape of remote skylights to concentrate sunlight and filter it underground through fibre optic helio tubes to turn an abandoned subway into a new underground park.

In the interview on p76, Shay says, “Not all towns want a High Line,” and a park is not always going to be the answer. For some cities, these stranded assets could be used for ecological restoration or to mitigate the effects of climate change. The Los Angeles River project aims to revitalise an 11 mile section of Los Angeles’ concrete encased river by stripping out the concrete bed and creating a green corridor where wildlife can flourish.

As Alice Shay says in our interview, “Infrastructure is the manifestation of our collective investment in the functioning of our urban places.”

It’s important we don’t allow that investment to go to waste.

In Paris, various proposals have been suggested to transform up to 16 disused metro stations. Proposals include the creation of

These projects all work best when the local community is involved. Local people often know best what they want and need.

As Alice Shay says in the interview: The circular economy of our infrastructure is a big challenge and an opportunity. It is essential that we, as designers and urban strategists, work towards ensuring that our collective investment in infrastructure allows us to live sustainably and equitably together in our cities.

Magali Robathan, managing editor, CLAD