  The inclusive e^+ p single and double differential cross sections for neutral
and charged current processes are measured with the H1 detector at HERA. The
data were taken in 1999 and 2000 at a centre-of-mass energy of \sqrt{s} = 319
GeV and correspond to an integrated luminosity of 65.2 pb^-1. The cross
sections are measured in the range of four-momentum transfer squared Q^2
between 100 and 30000 GeV^2 and Bjorken x between 0.0013 and 0.65. The neutral
current analysis for the new e^+ p data and the earlier e^- p data taken in
1998 and 1999 is extended to small energies of the scattered electron and
therefore to higher values of inelasticity y, allowing a determination of the
longitudinal structure function F_L at high Q^2 (110 - 700 GeV^2). A new
measurement of the structure function x F_3 is obtained using the new e^+ p and
previously published e^\pm p neutral current cross section data at high Q^2.
These data together with H1 low Q^2 precision data are further used to perform
new next-to-leading order QCD analyses in the framework of the Standard Model
to extract flavour separated parton distributions in the proton.
