For trucking, concern for the environment focuses on air quality and avoiding harmful emissions from two sources: fuel consumption and engines. Motor carriers – and equipment manufacturers – utilize numerous strategies to reduce fuel consumption by fleets, and engine-makers must also meet stringent standards for emissions.
As a result, heavy trucks are cleaner than ever; in fact, in BC's Metro Vancouver region, heavy commercial vehicles produce only 5 percent of all greenhouse gas and smog emissions, according to statistics compiled by Metro Vancouver on air quality. Click here for a comparison with other emission sources.
Here are some of the methods the trucking industry is using to reduce emissions:
In cold BC climates, aerodynamic drag on vehicles in winter can be nearly 20 percent greater than at standard conditions due to the ambient air density.  For highway tractor-trailers, this results in about a 10 percent increase in fuel consumption from drag when compared to standard temperatures.
This fact emphasizes the importance of drag-reduction devices in BC.
Boat tails – rear-mounted devices for both tractors and trailers – can reduce tractor-trailer aerodynamic drag between 7.6 percent and 11.8 percent at 65 mph (104.6 kph). This corresponds to an estimated reduction in fuel consumption between 4.7 percent and 7.3 percent or an estimated annual savings between 2457 and 3797 litres for each tractor pulling a boat tail equipped van semi-trailer. Carbon dioxide (CO2) emissions would be reduced between 6707 and 10366 kg per vehicle annually.
In addition to boat tails, other tractor add-ons can have a significant impact on aerodynamic drag. Add-ons can add OR subtract from the aerodynamic efficiency of trucks:
New Generation Wide-Base Single Tires
Wide-base single tires, which replace two traditional-width tires, on a new combination tractor and trailer could reap annual fuel savings of about 2 percent. Wide-base single tires save fuel by reducing vehicle weight, rolling resistance and aerodynamic drag. A 2 percent reduction in fuel consumption translates into a CO2 reduction of more than 3 metric tonnes.
As show in the below table, New Generation Wide Base Single Tires (NGWBST) are more fuel efficient than traditional duals. 
Engine Emissions Dramatically Reduced
Vehicle emissions are controlled by engine standards and fuel standards that are set and enforced by the federal government. Canadian standards closely mirror US standards because of the concentration of production of trucks in the US and the volume of cross-border truck traffic.
Today's engine standard (effective since 2010), has reduced emissions of particulate matter, nitrogen oxides, and non-methane hydrocarbons to virtually zero.
The following graph illustrates the change in truck engine emission standards from 1984 to 2010:
Fuel standards have also played an important role because regulation of the components in diesel fuel has a direct impact on emissions and smog. Since 1998, Canada has mandated low-sulphur fuel of no greater than 500 ppm for use in trucks. A 2006 standard for ultra-low-sulphur diesel further reduced sulphur content by 97 percent to 15 ppm. Today's diesel fuel is cleaner than the gas used in most cars.
Driver Training & Technology are Formidable Partners
Even highly experienced drivers can boost their skills with training aimed at improving fuel economy. Driver training programs consist of such things as learning about progressive shifting, engine speed optimization, idle reduction, smoother braking and acceleration, anticipatory driving, speed control and optimal gearing.
The table below shows approximate savings potential for key behavior/advice categories: 
Long combination vehicles (LCVs) are exactly what they sound like - a tractor with 2 and sometimes 3 trailers that exceed maximum legal length, but don't exceed maximum legal weight. This means that more goods can be transported in fewer trips using fewer trucks. Fewer trucks means fewer emissions.
LCVs are already used in 5 Canadian provinces (including BC), 21 US states, and Mexico. Because of strict permit conditions, the LCV safety record is even better than the safety record of traditional tractor-trailers, which is already considered commendable (see Safety for more details on the trucking safety record).
 Patten, J., McAuiliffe, B., Mayda, W. and Tanguay, B. (2012). Review of Aerodynamic Drag Reduction Devices for Heavy Trucks and Buses. National Research Council Canada Centre for Surface Transportation Technology.
 Center for Transportation Analysis at Oak Ridge National Laboratory, (2009). Effect of Wide-Based Single Tires on Class-8 Combination Truck Fuel Efficiency. National Transportation Research Center, Table 3.