Phil Mason, a British chemist who runs a Youtube vlog, made a similar argument about cost, adding his doubts about traction on a glass surface.[22] Solar Roadways conducted its own lab tests using a British Pendulum Skid Resistance Tester the texture was "sufficient to stop a vehicle going 80mph (129kph) on a wet surface in the required distance".[23] US Department of Transportation engineer Eric Weaver commented on Solar Roadways' safety tests, saying: "We can’t say that it would be safe for roadway vehicular traffic.