Labs testing roads deliver rubbery figures Save Share Laboratories testing asphalt, a key ingredient in surfacing roads, have been falsifying results of mixtures made at plants to inflate their apparent quality. The manipulation of figures can affect aspects such as the strength of the road-surfacing material and raises the risk of taxpayer-funded roads deteriorating more quickly than expected, industry sources say. Industry insiders say some tests for asphalt quality have been manipulated. Glenn Hunt As revealed in Industry sources said some in-house labs had been artificially boosting the quality of asphalt produced at their plants. Related Quotes Advertisement Testing is often done in-house and pressure to change results exists. That is because clients can hit suppliers with financial penalties or even demand a new batch if asphalt fails to meet specifications.