Entrepreneur Elon Musk has been given written permission to begin digging a transportation tunnel in Washington DC, which could eventually facilitate a 29-minute journey between the capital and New York City. More
The French operator of the Channel Tunnel has given the Boris bridge proposal a boast, by writing a letter to the UK prime minster in support of a second permanent connection between England and France. More
American firm The Miller Hull Partnership has completed a firehouse in the Pacific Northwest with large bi-fold glass doors that enable a quick exit for emergency trucks. More
Dutch office UNStudio has designed a cable car system for Gothenburg that will be supported by a network of latticed towers based on shipyard cranes. More
Architecture practice Gensler and footwear giant Reebok have revealed a concept to convert American petrol stations into fitness centres that generate energy. More
CF Møller Architects and Reiulf Ramstad Arkitekter have teamed up to design a tower at Oslo's central station, which will have a telescopic form to facilitate plant-covered terraces. More
Italian architect Carlo Ratti has unveiled a concept for a smart road system, which would feature swarms of drones that deliver first aid, monitor traffic and detect accidents. More
Danish architecture firm COBE has unveiled a concept for modular electric-car charging stations, which are set to be built in all three Scandinavian countries. More
The Democratic Unionist Party has backed a crossing between Northern Ireland and Scotland, proposed in response to Boris Johnson's suggestion to build a bridge between Britain and France. More
UK foreign secretary Boris Johnson has proposed building a bridge across the English Channel to link Britain and France after Brexit. More
A deliberate sway is designed to unnerve visitors to this 488-metre-long suspension bridge in China's Hebei province, which has an entirely glazed walkway so they can also admire the 218-metre drop. More
Danish firm BIG has developed a proposal to protect the San Francisco Bay from flooding caused by climate change, which includes building floating villages connected by ferries, a red-hued cycle route, and a highway for autonomous vehicles. More
Rising water levels don't cause many problems for this bridge in the Dutch city of Nijmegen – it can still be accessed even when the path on either side is flooded, thanks to a series of concrete stepping stones. More
A flood defence system devised by CF Møller in central Denmark will combine urban planning, climate change adaption and nature conservation. More
The controversy surrounding President Donald Trump's wall between the US and Mexico continues, as updated plans bring the predicted cost to $33 billion, while a petition has been launched to designate the eight construction prototypes as a national monument. More
A man-made island surrounded by wind farms in the middle of the North Sea could help bring large-scale renewable energy to Europe by 2050. More
British architect Will Alsop has created metro stations in Toronto's Pioneer Village and Finch West neighbourhoods, as part of an initiative to create more public transit options in the wider metropolitan area. More
Alt Arkkitehdit has completed a bright red storage shed for oil-spill equipment in northern Finland, featuring a full-width clerestory window that projects from the facade to protect it from damage by forklift trucks. More
California architecture firm Brooks + Scarpa has wrapped a Seattle transit facility in an undulated, blue aluminium screen that was influenced by a dance performance. More
Urban-Think Tank has completed the next phase of its Empower Shack project, bringing safe low-cost housing to residents of South Africa's informal settlements. More