As the State agency which has a duty to provide the public transportation, the Defendant No.1 has to provide public buses and other buses operated under the responsibility of the Defendant No.1 sufficient for people’s convenience and maintain these buses in good condition by not contributing pollution to the environment and public health according to the provision of Constitution and concerning laws. As a result, the failure to control vehicle emissions from these buses is the negligence of duties of the Defendant No.1.