How would you fancy riding your bike on an enclosed cycle lane high above the rooftops?
A group of architects made the futuristic designs to help people in London get to work quickly and safely - away from cars and traffic.
The cycle lanes, designed by Exterior Architecture, could run alongside train tracks to help cyclists zip around the city.
The mayor of London, Boris Johnson, says he thinks the idea is "exciting" and his team are looking into it.
But there'll be a lot of work to do before a project like this can become reality.