Self-driving cars rely on a bevy of sensors — including cameras, lidar, and radars — to navigate their complex surroundings. But sight is no substitute for maps, and with over four million miles of roads in the U.S. alone, collecting that data is no small feat. That’s where Carmera comes in.

The Brooklyn-based startup, which launched in June 2017 after spending two years gathering three-dimensional maps of New York City with lidar-equipped vehicles, today unveiled a real-time event management engine that facilitates quick, up-to-the-minute updates to said maps.

It also announced a partnership with the City of New York and a $20 million funding round led by GV, Google’s venture capital arm, with participation with prior investors including Matrix Partners.

Above: An animation demonstrating Carmera’s 3D mapping solution.

Image Credit: Carmera

Carmera’s new and improved platform — which is being deployed in cities including New York, San Francisco, Seoul, and Tokyo — taps a database of crowdsourced, high-definition maps sourced from vehicle fleets to derive insights from construction, police activity, traffic signals, turn restrictions, lane markings, and other events that might “have outsized impact” on ETA and disengagements.

“In designing this system, we learned a lot from our customers who are serious about commercial services — not just R&D or PR demos — and were frustrated by standard definition or incumbent mapping solutions that take months or quarters to update a simple feature,” Carmera wrote in a Medium post.

One of those customers is the New York City…