Comparing the properties of the sample of young massive stars with the general population, we find the RMS clouds are generally larger, more massive, and more turbulent. We examine the distribution of this subsample with respect to the location of the spiral arms and the Galactic bar and find them to be spatially correlated. We identify three significant peaks in the source surface density at Galactocentric radii of approximately 4, 6 and 8 kpc, which correspond to the proposed positions of the Scutum, Sagittarius and Perseus spiral arms, respectively. Fitting a scaleheight to the data we obtain an average value of similar to 29 +/- 0.5 pc, which agrees well with other reported values in the literature, however we note a dependence of the scaleheight on galactocentric radius with it increases from 30 to 45 pc between 2.5 and 8.5 kpc.