In a crowded field of more than 240 startups in self-driving cars, six companies -- four of them in Silicon Valley -- have achieved unicorn status, with valuations of $1 billion or more, according to industry estimates and publicly available data. Here's a closer look:
Velodyne LiDAR
Est value: $2 billion
Funding: $150 million
Founded: 2007
Headquarters: Morgan Hill, CA
Business: Lidar sensors
Investors: Ford, Baidu

Zoox
Est value: $1.67 billion
Funding: $290 million
Founded: 2014
Headquarters: Menlo Park, CA
Business: AV systems
Investors: DFJ, Lux Capital, AID Partners, Blackbird Ventures, Composite Capital

Quanergy Systems
Est value: $1.59 billion
Funding: $150 million
Founded: 2012
Headquarters: Sunnyvale, CA
Business: Lidar sensors
Investors: Daimler, Delphi, Samsung, Sensata, Motus Ventures, Alrai Capital, GP Capital, Newbury Ventures, Wicklow Capital, Wardenclyffe Partners

LeddarTech
Est value: $1.33 billion
Funding: $122 million
Founded: 2007
Headquarters: Quebec City, Quebec, Canada
Business: Lidar sensors
Investors: Delphi, Magneti Marelli, Osram, Integrated Device Technology, Access Capital, BDC Venture Capital, Go Capital, Desjardins Venture Capital, Innovatech Quebec, I-Source Gestion

ClearMotion
Est value: $1.25 billion
Funding: $130 million
Founded: 2009
Headquarters: Woburn, MA
Business: Software
Investors: Qualcomm, Bridgestone, JP Morgan, New Enterprise Associates, Acadia Woods Partners, Eileses Capital, World Innovation Lab

Nauto
Est value: $1.06 billion
Funding: $174 million
Founded: 2015
Headquarters: Palo Alto, CA
Business: Data
Investors: BMW, Toyota, General Motors, Allianz, Softbank, Greylock Partners, Playground Global, Draper Nexus, Index Ventures, Maniv Energy Ventures, Trucks VC
Sources: CB Insights, TechCrunch, Funderbeam, Crunchbase