Equipment that is prohibited by federal or State law may not be tested. Equipment that may pose a danger to the public may not be tested. Equipment may not be tested on vehicles that are mechanically unfit and unsafe to be operated on the highway. The Administration may place further restrictions on certain equipment, if necessary. Approvals. Equipment may not be installed on a vehicle without the written approval of the: Administration; and Director of transportation, if the vehicle is operating for a public school system.