Dataset for study: Cleaning up our acts: Psychological interventions to reduce engine idling and improve air quality

List and descriptions of the variables included (the same information appears to tab2 of the Excel document)

Condition - "experimental condition: 0 = baseline, 1 = social norm, 2 = outcome efficacy, 3 = private self-focus"

simple_norm - dummy contrast code used to assess the effect of Number of vehicles in the Social Norm condition

simple_selffocus - dummy contrast code used to assess the effect of Number of vehicles in the Private Self-Focus condition

Date - date of observation (MM/DD/YYYY)

Session - represents one barrier drop, numbered from 1 for each observation day (used for multilevel grouping)

Number_vehicles - number of vehicles queuing at one location, for each barrier drop (session)

humidity - average humidity measured for the duration of the barrier drop

O3 - average O3 concentration level measured for the duration of the barrier drop

logNO2 - logarithmic transformation of NO2

logPM25 - logarithmic transformation of PM25

Engine_off - whether engine is on or off, 0 = engine on, 1 = engine off