For statistical pass-by measurements (SPB) of road traffic according to ISO 11819-1 certain minimum distances between the measured vehicles must be guaranteed to achieve a sufficient source separation. The goal is to use beamforming with flexible directivity patterns to improve the source separation and as a result reduce the dependency on the uncontrollable traffic. Also the problematic ambient noise for controlled pass-by measurements (CPB) with electric cars at low speeds should be reduced due to the directivity. Only linear arrays with a maximum count of 15 microphones are used and to find an optimum in the earliest stage different geometries with different beamforming algorithms are simulated. Controlled pass-by measurements with two or more vehicles will be performed to evaluate the possibilities of the source separation by the array. Also the received pass-by levels of the array can then be compared to the levels calculated according to the corresponding norm.