Saturday, March 25
The map below is a 1-hour snapshot. Click to view all hours recorded since midnight.
The Sacramento region's Spare The Air program began in 1995. It is designed to urge drivers
to voluntarily reduce their driving on days when air pollution is approaching unhealthy levels,
while keeping the public informed about the daily air quality forecast and the health effects
caused by air pollution. Since the beginning, the effectiveness of the program has been measured
annually through telephone surveys conducted with residents of the Sacramento region on both
Spare The Air days as well as on non-Spare The Air, or Control, days.
Awareness of the program, self-reported driving reduction, and estimated emission reductions are
all used in evaluating the program. The use of Control-day interviewing increases the accuracy
of the evaluation as it corrects for possible over-estimation of the impact of the program as well
as possible over-stated driving reduction due to air quality concerns.
Previous research has shown there is a fairly complex relationship among the number of Spare The Air
days in a given summer season, the intensity of the episodes (single day vs. multi-day episodes)
the advertising budget and media coverage, the temperatures experienced during the season, whether
extraordinary events such as wildfires occur, and awareness of the campaign as well as voluntary
driving reduction on the part of residents.
Historical Survey Results