Streamwise high vorticity rolls and streaks in the turbulent channel flows have been the subject of many studies due to their important role in turbulence production, as a result of sweeping, ejection, and bursting of these structures. Understanding the physics of these streamwise structures is important in controlling drag producing events. Investigations of the average streak spacing of the low‐speed streaks have resulted in the generally accepted range of &lgr;+=&lgr;¯u&tgr;/&ngr;=100±20, where &lgr;¯ is the mean spanwise spacing between streaks, normalized to the viscous length &ngr;/u&tgr;. It is also reported, fory+≤30, that the streak spacing grows nearly linearly with distance from the wall. The previous studies mostly have focused on distances close to the wall. Here we report on correlation measurements extended into the log layer, which show that the linear growth of the vortex diameter and the streak spacing extends well in the log layer. Arguments are presented to distinguish these two measures. ©1995 American Institute of Physics.