Prior to the 1990’s testing for drivers was common, but not necessarily a mandatory thing, and for the most part drivers were only tested for things like alcohol but not necessarily any drug use. Tests were done mainly when accidents occurred to make certain that the drivers had not been under the influence of any substances when the accident happened. But of course, at the beginning of its inception tests were mostly done to see if alcohol was present.

Saliva tests are the most common ones done by police officers and can detect the most commonly used drugs made easily available on the street (Marijuana, Cocaine, Opiates, Mehtamphetamines, Ecstasy, and most sedatives).

There are many forms of tests currently out there: urine, saliva, hair, blood, sweat, etc… But the most commonly done tests (urine and saliva) can only detect a recent usage whereas testing hair or sweat can go back much further in a person’s history than normal testing can. But of course the question of cost is usually put into the mix. Companies have to ask whether or not these tests are cost effective. The shorter a time period the test can go back in a person’s history, the cheaper the test is to have done. The more extensive tests like hair and sweat which can give a much longer view of personal drug abuse in someone’s system are for more expensive. Companies have to make decisions in the short term like this regarding their policies to see what is more worth it to them.