The CBC News is reporting that the Justice Minister is considering amending Canadian laws to allow for random breathalyzer testing of all drivers, regardless of whether there is any reason to believe that the driver is intoxicated. See: CBC News - Canada - Random breathalyzer tests considered for Canada.
I read a lot of the posts on the CBC site, and all of them seem to assume that a breathalyzer test is 100% accurate. No instrument is 100% accurate, there will be false positives and false negatives from the tests. I don't know the chemistry used in breathalyzers, but I'd guess there are medications or other chemicals besides alcohol that cause it to give a positive reading.
ReplyDeleteWhen the test is only administered after seeing other evidence of intoxication, it gives reasonably strong evidence. However, if it is used to screen people where there's no other evidence, the proportion of false positives will go way up.