The Maryland State Highway Administration (SHA) retrofitted 181 of its model year 1990 – 2004 dump trucks with high-efficiency (i.e., 40 percent total PM reduction) diesel oxidation catalysts (DOCs).   Prior to the DOC installations, sample candidate vehicles were data logged to determine their suitability for diesel particulate filter (DPF) retrofits.

  Martin O'Malley Quote
  Table of lifetime emission reductions for the MD SHA On-Road Retrofits Project  

Data logging results indicated that the exhaust temperature profiles were borderline for passive DPFs, and DOCs were determined to be the best fit for SHA’s fleet.  The dump trucks operate year-round in Baltimore City and ten counties throughout Maryland, and are called upon for extra duty during difficult weather conditions such as snow storms. 

With a grant from U.S. EPA, under the American Recovery and Reinvestment Act (ARRA), MARAMA was able to provide full funding for all DOC equipment and installation costs.  Additional funding from SHA provided for replacement filters. 

Total cost:$251,764 ($231,154 grant funded)