I just realized that your original posting was submitted under the Schools section. Apologies. As you correctly identified, a designated carpool drop-off area is required for low-emitting and fuel efficient vehicles for school projects. The term "designated" is used to ensure that carpool drivers of low-emitting vehicles receive some sort of preference over drivers of conventional vehicles. Your proposed approach of having a designated lane for carpool drivers of low-emitting vehicles seems to meet the intent; however an official ruling on this must come from GBCI via the CIR process.