President Obama signed the Fixing America’s Surface Transportation (FAST) Act on December 4, 2015, a law that funds improvements to the nation’s roads, bridges, transit systems, and rail transportation network for a period of five years.

Among other things, the FAST Act directs the U.S. Department of Health and Human Services (DHHS) to issue scientific and technical guidelines for the use of hair testing for drugs for commercial motor vehicle drivers within one year of enactment of the Act. Once DHHS does so, motor carriers regulated by the Federal Motor Carrier Safety Administration will be permitted to use hair testing for drugs for pre-employment purposes as well as for random drug tests, if the driver was subject to hair testing for pre-employment purposes. Drivers with established religious beliefs that prohibit the cutting or removal of hair shall be exempt from hair testing.

Hair testing differs from urine testing in that there is a longer “look-back” period, i.e., hair testing will show whether an individual has used drugs within the last 90 days. Hair testing cannot determine very recent use, however – because hair grows slowly – so hair testing cannot be used for reasonable suspicion drug tests or post-accident testing.

Some trade groups opposed the hair testing provision, arguing that hair testing is not reliable and may be racially biased.