The head of the National Highway Traffic Safety Administration said that the agency will revise how it conducts a research program on whether drivers are using drugs and alcohol behind the wheel in the face of criticism from some members of Congress, reports The Detroit News.

Acting Administrator David Friedman told a House panel that NHTSA has decided to drop the use of an air sampler of drivers’ alcohol use in a national roadside survey — to “make sure we get their consent first” and to emphasize that it will only collect data from participants who are willing to participate and that all data is anonymous.

“It’s also important to note: this is a voluntary survey that collects anonymous data,” Friedman told the House Transportation Committee’s panel on highways and transit. “I believe we take every effort to make sure that is clear.”

Source: The Detroit News