Exposure to air pollutants in transportation microenvironments contributes a significant fraction to total pollutant exposure for city dwellers, particularly, in cities with mobility challenges where duration of exposure to traffic related pollutants can be considerably higher. This work assesses the factors influencing particulate matter exposure and inhaled dose in transport microenvironments in a large and rapidly growing metropolitan area. We determined the influence of transport alternative on inhaled dose by quantifying and comparing the dose of commuters in different transportation modes. The intake dose of fine particulate matter (PM2.5), equivalent black carbon (eBC), and number of sub-micron particles (Np) was measured for commuters in Bogotá, Colombia. The impact of travel mode, traffic load, and street configuration on dose and exposure were explored. Two active modes (walking and cycling) and a variety of motorized modes (bus, car, taxi, and motorcycle) were included in the study. Exposure concentrations of PM2.5, eBC, and Np were measured for commuters traveling a predefined path simultaneously using different transportation alternatives. The pollutants were measured continuously using laser based methods, aethalometers, and miniature diffusion size classifiers. Physical activity level associated to each commute alternative was determined with portable activity monitors and used to infer corresponding inhalation rates. Three different streets, all with similar length but widely different traffic composition and load were considered. Extremely high average eBC concentrations, ranging from 20 to 120 µg/m3, were observed throughout the campaign. The highest average concentrations of PM2.5, eBC, and Np were measured inside Bus Rapid Transit (BRT) system vehicles. These concentrations were significantly higher than those in any other mode studied. Pedestrians and bicycle users in an open street configuration experienced the lowest average concentrations of PM2.5 and eBC, six times lower than those in the BRT buses. However, pedestrians experienced the highest particulate matter intake dose in the road segments studied. Exposure concentration inside the fleet of diesel buses was significantly higher than the concentration exposure of pedestrians and bike users. The BRT system buses were consistently found to be the most polluted transport microenvironment among the ones considered in the study. The extremely high concentrations of eBC, as well as the eBC/PM2.5 ratio imply a large contribution from Diesel engine emissions to the fine particulate concentrations. Bogotá’s BRT system currently transports nearly 2.4 million passengers daily, suggesting that the high pollution levels inside the bus cabins can affect a substantial population.