Original sentence: CRVs are responsible for about half of all vehicle emissions in the PRC.Chinese Rural Vehicle (CRV) operators can be subject to fine by authorities (police) if the vehicle emits visible smoke.Regulations are administered by province/economic region/city as appropriate
Edited sentence: Chinese Rural Vehicle (CRV) operators can be fined by the police if their vehicle emits visible smoke.Regulations are established and enforced by province/economic region/city as appropriate