How San Francisco Is Using Lasers as an Urban Planning Tool
San Francisco’s Market Street is one of the most important transportation routes in the city, but urban planners are looking to reinvent it. Before they can transform the road into a vibrant public space, however, they first need to shower it with millions of laser beams.
LiDAR technology can be used to generate perfect, three-dimensional maps of cityscapes in a fraction of the time it would take on-the-ground surveyors. In the case of Market Street, San Francisco will be mounting a LiDAR system called a Riegl VMX-250 onto the roof of a truck, from which it will bounce lasers off surrounding surfaces and detect those beams upon their return. To build as accurate a map as possible, the truck will drive the length of the street four times at a speed of 5 mph. Along the way the laser system will construct 3-D point clouds of everything surrounding the truck from overhead wires to fire hydrants. The mechanism is so sensitive that it’s even able to capture the textural differences between pavement and painted parking lines.
This technology is obviously a useful tool for city planners, but LiDAR also has applications in numerous other fields. Scientists have used it to map topography shifts after natural disasters as well as the destruction of the world’s forests. Earlier this year, Baltimore implemented LiDAR systems to assess damage following its wave of riots. Cities and companies also use the technology to keep track of neglected infrastructure.
In San Francisco, they’re hoping the futuristic mapping tool will help them inject new life into a historic part of the city. That is, unless a little rain gets in their way, as it did this past weekend when the city was forced to postpone the run. When rain drops fall they create noise in the data, leaving a map that's spotty and hard to decipher. The scan has been rescheduled for a weekend in December, weather permitting.