TracePro is a ray tracing program for designing and analyzing optical and illumination systems. It is the first optics software based on the industry-standard ACIS solid modeling kernel from Spatia. A light collimating system and a Cassegrain collector with spherical mirrors for non-dispersive infrared sensing of vehicle emissions is simulated by TracePro. This system can be used to monitor density of pollutants such as HC, CO and CO2 emitted by vehicles on road of 15 m width. This optical design is analyzed by TracePro and the design is modified according to the analysis report and reference data for subsequential mechanical design, assembling and adjustment can be provided.