-3- 



should be by regulations proposed by this Division for N.C. 

 Environmental Ilanagement Comnission adoption. 



Since the enforcement of the existing safety inspection 

 program through a windshield sticlcer system has been well 

 established, it is appropriate that the inspection/maintenance 

 program also be enforced through a sticker system. Enforce- 

 ment through the registration system (e.g., denial of 

 registration v/ithout emission test) does not appear to offer 

 significant advantages over the sticker system if the sticker 

 system includes a comprehensive effort by the law enforcement 

 agencies. 



Gasoline-powered motor vehicles are the main contributors to 

 carbon monoxide pollution, whereas diesel-powered m.otor 

 vehicles, although associated v;ith higher visible emissions, 

 are relatively minor sources of carbon monoxide. A requirement 

 for diesel-pov/ered vehicles to participate in the inspection/ 

 maintenance program would not accomplish a significant reduction 

 in carbon monoxide. Similarly, vehicles which are older than 

 twelve (12) years contribute only a small portion to the total 

 carbon monoxide emissions mainly because these vehicles 

 constitute only a small percentage of the vehicle fleet. 

 Vehicles older than twelve years often account for less than 

 three or four percent of the total miles traveled in an area, 

 and many of these vehicles are ovmed by persons in low-income 

 groups. Thus, inspection/maintenance of these older vehicles 



