On the Road

Simple steps start with fewer car trips.

Vehicles contribute to about one third of all ozone-causing emissions in the Denver area. That makes reducing vehicle trips an effective way to help our air quality, and doing your part may be easier than you think.

Skipping trips. One person who takes two fewer vehicle trips each week will keep 14 pounds of ozone-causing emissions out of our air each year. Imagine what 1,000 or 10,000 people can do? These don’t have to be long trips either. Some ways you can skip a couple of car trips each week include:

  • Packing a lunch or walking to lunch.
  • Walking, jogging, or riding a bike to the gym.
  • Using public transit to get to a game, concert, or other event.
  • Making a grocery list, and checking what you have in the house so you don’t have to make a second trip to the store.
  • Shopping for items online when possible.
  • Carpooling with friends and family when possible.

Combining trips. Sometimes you just need to drive. It happens. You can still help our air by combining trips. Think of it as the “while I’m out,” approach. These steps can help save the air, and save you time as well:

  • Pick one day to run errands each week. You can even put an “errand bag” or box in your vehicle and fill it with items or reminders so you won’t forget anything while you’re out.
  • Time errands for when you’ll be out anyway: like on the way home from work, or after dropping kids off at school or team practices.
  • Try to keep stops to 30 minutes or less.

About that last one…chances are, like most vehicles on the road today, your vehicle has a catalytic converter which helps reduce emissions. When you start your vehicle, heat from engine exhaust creates a chemical reaction in the catalytic converter that reduces harmful emissions. However, if your vehicle has been off for an hour or more, it could take several minutes for the catalytic converter to heat up enough to start working – even in summer. A vehicle that’s been off for one hour produces four times the amount of emissions as a vehicle that’s been off for 15 minutes. If you can get in and out of the hardware store, pet store, library, or sporting goods stores in half an hour you’re helping the air.

Here are some other simple steps involving your vehicle that can help Colorado air:

  • Avoid idling your car while waiting in parking lots or service lines. Turn off your engine instead.
  • Refuel in the evening so fuel vapors don’t have a chance to “cook” into ozone.
  • Keep your car tuned up and tires well inflated to increase mileage and reduce the need for refueling.
  • Don’t overfill your car when refueling. When the nozzle clicks off your tank is full. Also, wait a few seconds before removing the nozzle to keep fuel from dripping onto the ground.
  • Consider making a smart vehicle choice like an alternatively fueled vehicle (i.e., electric vehicle, hybrid) or one that gets good gas mileage the next time you are buying or renting a car.

The Regional Air Quality Council is involved in several other vehicle-related programs aimed at improving our Colorado’s air. Find out more about these programs below.

Don’t Be Idle. An idling vehicle gets the worst gas mileage possible – 0 MPG. We hope to dispel many myths about idling vehicles, including the idea that you use more fuel turning your car on and off. That is simply not true. If you plan to idle for more than 30 seconds, please turn off your engine. For more information, visit the Denver coalition web site at

Easy Fixes. Vehicles that run on diesel fuel are as sturdy as they come. Often though, these vehicles produce high levels of pollution that can be easily reduced by retrofitting simple exhaust system components and adding idling reduction technology. The RAQC and its partners have a robust retrofit program designed to reduce emissions from school buses, semi-trucks, government and commercial fleets as well as heavy duty vehicles. These projects help to reduce pollution by changing parts out instead of having to replace the vehicles all together. For more information, visit

Transport Yourself Differently. There are many alternative ways to get around other than single-occupancy vehicles. The RAQC is spearheading an effort to get people out of their cars only two trips per week. To find out more information, visit The Denver Regional Council of Governments has additional information about other programs and efforts throughout the Denver-metro region on its website.