  {} {To quantify the amount of chaos that exists in the local phase space.} {A
sample of orbits from four different models of the Solar neighbourhood phase
space are analysed by a new chaos identification (and quantification)
technique. While three of the used models bear the signature of the
perturbation due to both the Galactic bar and the spiral pattern, the last of
the models is a bar only one. We explore the models by inter-comparing the
corresponding values of chaos strength that is induced at the various energy
levels .}{(1) We find that of all the viable models that have been demonstrated
to successfully reproduce the local phase space structure, i.e. those that
include the bar as well as the spiral, bear strong chaoticity, though the model
that implies the highest degree of chaos is the one in which overlap of the
major resonances of the bar and the spiral occurs. The bar only model is found
to display regularity. (2) We advance chaos to be primarily responsible for the
splitting of the Hyades-Pleiades mode (the larger mode) of the local velocity
distribution}{}
