Uber, working to resume tests of its self-driving vehicles after a fatal accident earlier this year, is laying off test-vehicle operators as part of a broad overhaul of the program.

An Uber spokeswoman confirmed the elimination of operator positions in Pittsburgh, a key market for the ride-hailing company’s self-driving initiative, but some of those personnel may be moved to one of the 55 new “mission specialist” roles handling both on-road and test-track duties.