  We study the collimation of radio jets in the high-luminosity Fanaroff-Riley
class II sources by examining the dependence of the sizes of hotspots and knots
in the radio jets on the overall size of the objects for a sample of compact
steep-spectrum or CSS and larger-sized objects. The objects span a wide range
in overall size from about 50 pc to nearly 1 Mpc. The mean size of the hotspots
increases with the source size during the CSS phase, which is typically taken
to be about 20 kpc, and the relationship flattens for the larger sources. The
sizes of the knots in the compact as well as the larger sources are consistent
with this trend. We discuss possible implications of these trends. We find that
the hotspot closer to the nucleus or core component tends to be more compact
for the most asymmetric objects where the ratio of separations of the hotspots
from the nucleus, r_d > 2. These highly asymmetric sources are invariably CSS
objects, and their location in the hotspot size ratio - separation ratio
diagram is possibly due to their evolution in an asymmetric environment. We
also suggest that some soures, especially of lower luminosity, exhibit an
asymmetry in the collimation of the oppositely-directed radio jets.
