Experimental Safety Vehicle (ESV) is the designation for experimental concept cars which are used to test car safety ideas.
In 1970 the U.S. DOT announced its ESV project, the aim of which is to obtain safer vehicles by 1980. [1]
In 1991, the ESV abbreviation was backronymed to Enhanced Safety of Vehicles. [2]
ESVs should not be confused with safety cars.
NHTSA Page of ESV Conference Proceedings, 1998 (16th) to 2009 (21st): http://www-nrd.nhtsa.dot.gov/departments/nrd-01/esv/esv.html