Since lane changes influence traffic operations, it is useful to know their frequency for various conditions. This paper studies the number of lane changes as function of the roadway characteristics. Two sites are studied, for which individual lane change data is available. The paper shows that the most constant measure is the lane change rate, i.e. the nr of lane changes per veh km driven, which is approximately 0.5. It shows its maximum for densities just under the critical density. Furthermore, the lane change rate increases with an increase of the density in the origin lane for a constant density in the target lane. Surprisingly, the number of lane changes also increases with an increase of the density in the target lane for a constant density in the origin lane.