Roadside emission testing—bad law in a good cause?

In 1998, legislation was introduced in the U.K. on a trial basis that created the offense of failing a roadside emission test and which was punishable by a stiff penalty. Despite the severity of the measure, no involved party has any means of knowing whether the vehicle will pass or fail the test. Anecdotal evidence has suggested that "failures" are being recorded on vehicles that both before and after the roadside test satisfied the emission criteria. As a consequence of these and other features of the test procedure, there has been substantial criticism of these measures by motoring and consumer groups. This article reviews the environmental and legal issues associated with such testing regimes, and examines the potential likelihood of achieving an equitable scheme that will yield air quality improvements.