The tests were designed to determine whether it was possible to affect target speed measurement under a variety of environmental and operational conditions. The models tested were those identified in a Dade County, Fl., evidentiary hearing which held that the reliability of these devices has not been established beyond reasonable doubt. These models are the CMI Speedgun 6 and Speedgun 8, the Decatur Electronics MV-715, the Kustom Signals MR-7 and MR-9, and the MPH Industries K-55. Units were tested under conditions of shadowing, batching, panning error, scanning error, cosine errors, and errors due to the lock-on feature, heat build-up, power surge, mirror switch aiming, and internal and external interference. There was no observed degradation in performance of any of the units as a result of cosine angle effect, automatic lock, heat build-up, mirror switch aiming, or high tension wire interference. Only one of the units was affected by external CB and none was affected by police radio transmissions at distances beyond 30 feet from the radar. Some units were affected by internal electrical interference. CB transmission in the same vehicle as the radar affected nearly all units, while police radio transmissions had a limited effect on radar units. Shadowing affected all but one of the units, and target speed bumping affected three of the units. In all cases, two-piece radars were affected by panning. While the units tested were affected in varying degrees by test conditions, it appears that the sources of error can be avoided through proper installation and operation of the unit. Test methodologies and tabular data are appended. (Author abstract modified)