Our cars pollute less than they used to, but smog is still a serious problem. How did this happen? For one, in many places there are simply more of us, and that means more pollution. But we are also making bad decisions about how we grow. The sprawling development of our suburbs and cities is forcing us to drive farther and more often. Add to that the fact that cities are choosing to expand and build more roads instead of investing in clean public transportation, and it becomes obvious why smog and the quality of our air are still big problems.
More Transit, Less Driving: In the Portland metro area, the Tri-County Metropolitan Transportation District has increased monthly ridership for 12 consecutive years. Between 1990 and 1999, Tri-Met ridership outstripped vehicle miles traveled in the metro area.
In this report, the Sierra Club has graded America's largest cities(1) on the smog(2) from their transportation systems by looking at the amount of smog coming from cars and trucks per resident in relation to the cities' spending on public transportation. We found a clear relationship between increased investment in public transportation and decreased per person vehicle smog. The more our nation spends on reducing the number of drivers and the amount of time drivers spend on the road, the cleaner and healthier our air will be.
Despite Efforts, Smog Remains a Serious Health Problem
Smog is a serious public health threat. Twenty percent of our population lives in areas where doctors and scientists say the air is not deemed safe to breathe. Exposure to smog has been implicated in a range of illnesses and conditions, from asthma to pneumonia.(3) It may also worsen sinusitis and hay fever, and may trigger or aggravate cancer and emphysema. For people who live in the most polluted places, smog levels can be life-threatening.
We have long recognized smog as a problem. Despite that, smog has actually increased in a number of regions in the past 10 years.(4) In fact, only 10 to 14 of 207 polluted cities (fewer than 5 to 7 percent) saw a reduction in their air pollution in the 1990s.(5)
As a nation we've undertaken a variety of efforts to clean our air since the 1960s and '70s. In fact, we've made progress in creating "cleaner" cars. Cars today are typically 70 percent to 90 percent cleaner (depending upon the vehicle and pollutant being measured) than their uncontrolled counterparts of the 1960s. However, this gain is cancelled out primarily for two reasons. For one, half the new vehicles sold in the United States are SUVs or other light trucks, which produce more smog-causing pollution than cars because they get fewer miles per gallon. The boom in SUV ownership has meant that the fuel economy of the U.S. vehicle fleet is at its lowest point since 1980. And two, people are driving more.
Sprawl Forces Us to Drive Everywhere
Why are people driving more? Poorly planned development is leading to sprawl, lengthening trips and forcing us to drive more often. The average American driver spends 443 hours per year -- the equivalent of 55 eight-hour workdays (more than 10 work weeks) -- stuck in traffic. Residents of sprawling communities drive three to four times as much as those living in compact, well-planned, walkable areas. Adding new lanes and building new roads just makes the problem worse. Studies show that increasing road capacity only attracts more traffic and causes more sprawl.(6) As sprawl increases our reliance on cars and driving, it makes our air dirtier and less healthy.
Making the Clean Air Grade
The Sierra Club researched and evaluated the steps our nation's largest cities are taking to help people drive less and create cleaner air. In the context of each city's total smog problem, we analyzed the proportion of smog coming from cars and trucks per resident, and the amount spent in that state to promote more public transportation choices. We then graded each of our nation's largest cities on these two criteria:
(1) smog from cars and trucks in their city, and
(2) the extent to which they are taking advantage of the opportunity to clean up their air by focusing state spending on clean transportation choices as opposed to building new roads.
Our research reveals that the more states spend on public transportation, the less car and truck smog is created per person in our largest cities. The chart (open in a new window) tells the story.
Reports by regional air districts were used to determine grades for the 50 largest cities for smog from cars and trucks. This allows us to see the part of the air pollution problem for each city coming from car and trucks. Grading cities based on smog per person from cars and trucks shows how well they are reducing pollution from their transportation systems. Based on the pounds of smog from cars and trucks per person annually, the grading scale used here is:
Bus Me Out to the Ballgame: Denver is one of many cities that have built new baseball stadiums downtown, and rely primarily on public transit to get fans to the games.
|26-50 ||B |
|51-75 ||C |
|101 and up|| F |
The grading on transit funding is based on the amount spent per city resident on transit for every $100 spent on highways per person statewide. This shows how much a state balances spending on cleaner transportation alternatives versus more polluting road construction. We used the following grading scale:
|$101 and up ||A|
These two grades were then averaged using the following grading scale to produce a final grade (with half point increases/decreases for pluses and minuses):
|4 points ||A|
|3 points ||B |
|2 points ||C |
|1 point ||D |
|0 points ||F |
Spending to Offer Public Transportation Choices Creates Cleaner Air
This analysis points out the striking connection between pollution from transportation and spending on transportation choices. New York state, for example, received a high grade in terms of its spending on public transit, and is the only state in this grading that spends more money on alternatives than on new roads. At the same time, the New York City metropolitan area has the least amount of smog per person from cars and trucks. Oklahoma City received a low grade for having a high amount of smog from cars and trucks per person, while the state spends a paltry $5.80 on public transit for every $100 it spends on highway and road construction. Oklahoma completely fails in terms of spending on transportation choices versus roads.
Seven of the 12 cities with the highest grades for low car and truck smog per person -- New York, Chicago, Los Angeles, San Diego, San Francisco, Sacramento and Washington, D.C. -- are located in one of the five highest graded states for spending on clean transportation choices. This demonstrates the power of public transit as a tool in combating air pollution.
This research illustrates that providing people more transportation choices can significantly reduce automobile use, thereby reducing smog and the accompanying effects on public health. Conversely, limiting transportation choices by continuing to disproportionately fund new highway construction leads to ever more sprawling development and air pollution that threatens our well-being.
Our Leadership Should Stop Sprawl for Cleaner Air
Spending money on public transportation is a good investment that responds to public demand. According to the American Public Transportation Association (APTA), residents are increasingly turning to public transportation. In the past five years, public transportation ridership has increased by 21 percent.(8) Clearly, the public wants clean air and more public transportation choices. It is up to state and local governments to provide these options.
The Sierra Club recommends that the state and federal government:
- Increase the amount of money set aside for public transit and at least equalize funding between public transit and highways.
- Plan development wisely to shorten car trips and facilitate public transportation.
- Support public involvement in the transportation and land-use planning process.
Individuals can act now for cleaner air:
- Combine trips when you are running errands.
- Walk, bike, use public transit where available or carpool to work.
- Live near your work and near public transportation.
- Demand more public transportation choices in your community.
- Talk to decision-makers about the need for increased investments in public transit.
By better balancing transportation spending between roads and less-polluting public transportation, like rail transit and clean buses, we can reduce the number of miles people have to drive, provide Americans more transportation choices and better reflect America's priorities for clean air, good health and enhanced quality of life.