Yuo do drive tests with software and some equipement, you need special phones and connected GPS. Also, you need 2 persons min, for drive tests, one to drive a car and other to do measurements. You connect equipement, and measure everithing, C/I,Rxlevel, neighbouring tests, etc, but you must have Tems drive investigation.
i gues it has to do with the time of the drivetest. If you do it during the busy hour of the area you’re driving in, then it certainly is a “loaded” drivetest.
It impacts the success of HO, call setup, and it increases the amount of interferences (because more radio frequency usage)