The CASA Project on Non-Point Sources (2015 – 2017) was tasked with helping to address non-point source air emissions contributing to ambient fine particulate matter (PM2.5) and ozone standard non-achievement in Alberta and had a large focus on the transportation sector. This project was informed by recommendations from that project.

Based on the 2014 Air Pollutant Emissions Inventory, the on-road transportation sector is a large emission source of NOx (particularly heavy-duty diesel vehicles, followed by light-duty gasoline trucks and other vehicles), a source of volatile organic compounds or VOCs (particularly light-duty gasoline trucks and other vehicles), and a source of primary PM2.5 (particularly heavy-duty diesel vehicles). In 2012, the International Agency for Research on Cancer classified diesel engine exhaust as carcinogenic to humans based on evidence that exposure is associated with an increased risk for lung cancer. More recently, Health Canada published a document that categorizes the relationship between lung cancer and diesel exhaust as causal based on a weight-of-evidence analysis of epidemiological data as well as identifying a suggestive relationship between bladder cancer and diesel exhaust.

Previous ROVER Projects

The earlier ROVER (Roadside Optical Vehicle Emissions Reporter) I and ROVER II projects were completed in Alberta through CASA. In 1998, the ROVER project assessed actual in use vehicle emissions using a remote sensing van equipped to measure exhaust emissions including carbon monoxide. It also communicated with Albertans about vehicle emissions. During ROVER I, over 42,000 light duty vehicles were tested in Edmonton, Calgary, Red Deer, and Canmore. In 2006 the project was repeated as ROVER II, testing over 66,000 vehicles in the same four municipalities. This time the team measured exhaust emissions of nitric oxide, particulate matter, hydrocarbons, carbon monoxide, and carbon dioxide. ROVER II found emissions per kilometer were falling but vehicle use was increasing. Furthermore, the results indicated that although the number of higher emitters was relatively small at 5%, they contributed a larger proportion of emissions (60% of carbon monoxide, 31% of hydrocarbons, 26% of nitric oxide, and 7% of particulate matter).

Project Scope

The work of the project team will be limited to using remote sensing technology to test emissions from the in-use on-road vehicle fleet, including heavy-duty and light-duty trucks/vehicles, and making recommendations on managing emissions from the on?road transportation sector. 

The focus of this work is intended to be diesel-fuelled trucks but would also collect data on other heavy-duty vehicles (e.g., buses) and light-duty vehicles (e.g., personal vehicles). The emissions of focus include NOx, VOCs, CO, CO2, and particulate matter for a holistic approach (selected air contaminants and greenhouse gases) but recommendations to reduce these substances are expected to have the co-benefit of reducing other emissions.

Project Goal

To measure emissions from the in-use on-road transportation sector, particularly diesel-fueled trucks, to inform management actions and/or next steps for transportation emissions management to help achieve the CAAQS in Alberta.

Desired Outcomes

Project work began in April 2018, with most of the light-duty vehicle testing being completed in 2020 and 2021. The remaining data collection, including the heavy-duty vehicle emissions, is being conducted over the summer of 2022. The project team will develop a final report with the collected vehicle emissions data, key findings, and recommendations.

For more information, please contact Project Manager Katie Duffett at  

Articles and Videos

Vehicle exhaust in Edmonton and four Alberta cities monitored as part of study on air pollution

Compile and review information and agree on a common understanding of current transportation emissions and their management in Alberta.

Undertake an on-road vehicle emissions testing study (or studies) to gather data on emissions from in-use on-road light-duty and heavy-duty vehicles, focusing on diesel-fuelled trucks.

Develop a vehicle emissions profile for the in-use on-road vehicle fleet based on data from Objective 2 and compare results from this and similar studies.

Evaluate and recommend management actions and/or next steps to reduce emissions from in-use on-road vehicle fleet based on the outcomes of Objectives 1 and 3.

Develop and implement a strategy and action plan for communicating the work of the project team, and on vehicle emissions and their impact on air quality.