Figure 6: Average instantaneous particulate matter (PM2.5; mg/m3) detected by the DustTrakR instrument at the first second-T1 (a), five seconds-T5 (b), and the sum of seven readings (c) as a function of vehicle speed for experiment sites in Mexico and the US. Small bars represent standard error. 1=Leyendecker, 2=Columbus, 3=Deming, 4=Anthony, 5=Bolson, 6=La Teja, 7=Palomas.