The methodology below describes how to use observed idle time as an indicator of idling reduction. Other options to measure program success could include air quality measurements or surveys. Observers can be parents/volunteers, students from high schools or middle schools or paid staff.

Changes in weather have a direct effect on idling behavior. When using the "medium plan," take into consideration the potential impact of the weather in a "before and after" method of evaluation. The use of a control school for each participating school can provide a reasonable comparison for evaluation.

• Have observers measure idling time with tracking forms and stopwatches. For baseline information, select schools that closely profile the participating schools (size, grade, urban-rural, etc.).
• Monitor the same schools for five consecutive days at the same time.
• For student drop-off, begin measuring idling times 30 minutes before classes start and continue measuring 20 minutes after class start time.
• For student pick-up, begin measuring idling times 30 minutes before classes end and continue measuring 30 minutes after school is dismissed.
• Randomly select cars as they arrive (every monitor should always be busy either timing a car or looking for the next available car in order to have the largest sample size possible).
• Indicators of idling vehicles include visible exhaust fumes, engine noise, a vibrating tail pipe, illuminated exterior lights.
• Things to be noted: weather conditions, idling time in minutes and seconds versus just seconds, driver gender, number of people in the vehicle.
• Things that could be noted: vehicle description, in-car activities (reading, radio, watching for child, talking to other parent, etc.), grade level of children being dropped off (many schools have different start times for primary and intermediate grades).