Motor vehicle noise is regulated by the pass-by provisions of ISO 362. Although motorcycle noise levels have fallen significantly, in line with the legal requirements, there is still a difference between noise levels for new and in-use vehicles. A research program was initiated to compare in-use motorcycle operating conditions with the requirements of the pass-by test. Ten current production motorcycles were monitored during actual urban driving conditions in several European cities during various driving periods. The results show the pass-by provisions of ISO 362 do not reflect actual in-use operating characteristics of modern motorcycles. To be representative, the test procedure should be based on engine rpm and not vehicle speed.