A hybrid-optical remote sensing (hybrid-ORS) method was developed to quantify mass emission factors (EFs) for fugitive particulate matter with aerodynamic diameters ≤ 10 μm (PM10) and ≤ 2.5 μm (PM2.5). In-situ range-resolved extinction coefficient and concurrent point measurements of PM10 and PM2.5 mass concentrations are used to quantify two-dimensional (2-D) PM10 and PM2.5 mass concentration profiles. Integration of each 2-D mass concentration profile with wind data, event duration, and source type provides the corresponding fugitive PM10 and PM2.5 EFs. This method was used to quantify EFs for fugitive PM10 and PM2.5 emitted from tracked and wheeled vehicles travelling on unpaved roads in a desert region. The EFs for tracked vehicles ranged from 206 g/km to 1,738 g/km for PM10 and from 78 g/km to 684 g/km for PM2.5, depending on vehicle speed and vehicle type. The EFs for the wheeled vehicle ranged from 223 g/km to 4,339 g/km for PM10 and from 44 g/km to 1,627 g/km for PM2.5. Field implementation of the hybrid-ORS method demonstrates that the method can rapidly capture multiple profiles of the PM plumes and is well suited for improved quantification of fugitive PM EFs from vehicles traveling on unpaved roads.