diesel truck

Truck & Bus

California’s landmark Truck and Bus Regulation calls for modernization of the state’s diesel fleet, with equipment upgrades and replacements phased in over time.

For decades, high-polluting trucks and buses have contributed a significant proportion of harmful emissions, negatively affecting the state’s air quality. They are responsible for approximately:

  • 90 percent of diesel pollution;
  • 80 percent of smog-forming pollution; and
  • 50 percent of greenhouse gas emissions.

CARB has adopted incentives and phase-in requirements that, over time, call for retrofitting or replacing all diesel trucks and buses operating on California highways. The result will be that by 2023, all larger trucks and buses in the state will be more than 90 percent cleaner than in the year 2000.

Get Assistance

Staff are available to provide compliance assistance for heavy-duty diesel vehicle regulations.