This paper outlines an approach for obtaining microphone array geometry for use in traffic noise analysis. The designed array has a smaller number of microphones compared to existing solutions, thereby reducing the cost of system realization. The array geometry is irregular, consists of 24 microphones, and was obtained by an optimization procedure that minimizes beampatterns sidelobes. Microphone position optimization was performed in the frequency band from 300 Hz to 2000 Hz, defined by traffic noise characteristics. The designed array is used in ongoing research dedicated to the analysis of angular distribution of incident traffic noise sound energy impeding a facade in urban environment.