From The Real Urban Emission (TRUE) Initiative and the Clean Air Strategic Alliance (with representation from SAGE):

Using real-world remote sensing data from vehicle inspection stations across Alberta, researchers analyzed the levels of excess nitrogen oxides (NOx) from the heavy-duty fleet to identify rates of tampering or malfunction.

Key findings include:

38% of model year 2010-2015 tractor trucks show evidence of tampering or malfunction.
Despite making up less than one quarter of the fleet, this group of vehicles is responsible for nearly half of Alberta’s total NOx emissions from tractor trucks.

By 2035, tampered or malfunctioning vehicles are estimated to increase total NOx emissions by 145% compared to a properly functioning fleet.
The real-world prevalence of these vehicles is up to 2.75 times worse than originally forecasted in a 2022 modeling study.

“We found it particularly interesting to see the difference between estimated rates of tampered or malfunctioning tractor trucks and the real-world data,” says Michelle Meyer, researcher at the International Council on Clean Transportation, the TRUE Initiative’s technical partner. “Our analysis shows once again the importance of collecting emissions data from vehicles on the road to develop effective policies to target high-polluting vehicles and improve air quality.”

Tampered or malfunctioning vehicles are projected to severely undercut the potential air quality and health benefits of recent emission standards.

Without immediate action, excess pollution from these trucks could lead to:

• 419 preventable deaths by 2035.
  For communities near roadways, exposure to these pollutants contribute to diseases including lung cancer, stroke, and chronic obstructive pulmonary disease.
• CAD $5.4 billion in health damages for Alberta communities between 2024 – 2035.
  Assuming no policy action is taken, damages this year alone would amount to CAD $358 million.