Photoactive roadways have been suggested as a mitigation method to improve air quality in urban areas. However, difficulties translating laboratory results to real world conditions has complicated a wider adoption of this technology. This work presents a methodology to determine first-order loss coefficients of ozone precursors on photoactive asphalt and concrete using a continuously-stirred tank reactor under different conditions of humidity and UV illumination. The experimental loss coefficients were used to determine uptake coefficients that can be incorporated in air quality models to represent photoactive surfaces. Palabras clave: Motorway