In Sacramento last year, the Council of Area Governments offered up to $50 in free gas to commuters who agreed to carpool with another passenger. The goal was twofold: decrease traffic congestion and improve air quality. Sacramento flunked the American Lung Association’s 2003 smog test, so there was a second incentive for sharing rides.

Des Moines consistently scores an “A” on the test, which measures the main ingredient in smog, ozone, a potent respiratory irritant that poses particular hazards to children, the elderly and those with chronic lung diseases, especially in the summer months. We take our air quality for granted in Iowa. We shouldn’t. Such complacency stands in the way of serious conversations about protecting the air quality that makes Greater Des Moines one of the most livable regions in the United States.

We’re hopelessly attached to our vehicles in Central Iowa and, for the most part, are unwilling to give up the flexibility that comes with traveling solo to work each day. Try counting the number of single-occupant vehicles among the 125,000 or so crawling along Interstate 235 during rush hour on any given weekday. Easier yet, tally those carrying two or more people.

We need to think more like Sacramento. A program the Greater Des Moines Transportation Management Association and Metropolitan Transit Authority are offering during “Stress-Free Commute Week,” May 10-14, is a start. Five-minute massages at the Kaleidoscope at the Hub will be offered to individuals who use mass transit instead of driving to work alone in their cars. The incentive package also includes eligibility for a drawing for prizes ranging from gift certificates to local day spas and malls to tickets to Iowa Cubs games.

Other initiatives, such as the TMA’s “Avoid the Rush” campaign to reduce Interstate 235 traffic by 10 percent by 2020, haven’t yet produced measurable results. That group is promoting carpooling, mass transit, staggered work schedules, compressed workweeks, walking, bicycle riding and telecommuting, but the traffic flowing in and out of the city hasn’t noticeably decreased.

Probably the strongest incentive to carpool can be found in spiraling gas prices, which could reach $2 per gallon by summer. High prices, and the continuing dependence on oil from unfriendly nations, ought to be enough to cause us to double up in our cars. But with SUVs and other gas-guzzling vehicles ruling the road, we wonder if air quality will have to plummet before people get serious about protecting one of Iowa’s greatest resources.