Structure and Dynamics of the Milky Way: The Evolving Picture
  From the inception of radio astronomy, the study of the Interstellar Medium
has been both aided and frustrated by one fact: we are right within it! Our
embedded perspective is favourable to observing kinematic and structural
details that are likely to remain inaccessible in external galaxies for some
time, but not so to gaining a birdseye view of our Galaxy's strucutre and
motions on the largest scales. The CGPS is the original survey with the ability
to image both details and the "big picture". We will broadly review what we
know of the Milky Way (MW), and focus on large-scale ISM structure and dynamics
that the IGPS family of surveys depicts particularly well (e.g. spiral
structure, the rotation curve, density waves, rolling motions, the warp &
scalloping). We also highlight areas where puzzles still exist (e.g. outer
spiral structure, the question of shocks and rolling motions in the MW), and
offer some new insights (e.g. multiple shocks in the 2nd quadrant; a radially
varying spiral pattern speed in the disc) demonstrating what is possible with
current and future high-resolution 21 cm surveys.
