  A new form of the Kerr-Newman solution is presented. The solution involves a
time coordinate which represents the local proper time for a charged massive
particle released from rest at spatial infinity. The chosen coordinates ensure
that the solution is well-behaved at horizons and enable an intuitive
description of many physical phenomena. If the charge of the particle $e = 0$,
the coordinates reduce to Doran coordinates for the Kerr solution with the
replacement $M \to M - Q^2/(2r)$, where $M$ and $Q$ are the mass and charge of
the black hole, respectively. Such coordinates are valid only for $r \ge
Q^2/(2M)$, however, which corresponds to the region that a neutral particle
released from rest at infinity can penetrate. By contrast, for $e \neq 0$ and
of opposite sign to $Q$, the new coordinates have a progressively extended
range of validity as $|e|$ increases and tend to advanced Eddington-Finkelstein
(EF) null coordinates as $|e| \to \infty$, hence becoming global in this limit.
The Kerr solution (i.e.\ with $Q=0$) may also be written in terms of the new
coordinates by setting $eQ = -\alpha$, where $\alpha$ is a real parameter
unrelated to charge; in this case the coordinate system is global for all
non-negative values of $\alpha$ and the limits $\alpha = 0$ and $\alpha \to
\infty$ correspond to Doran coordinates and advanced EF null coordinates,
respectively, without any need to transform between them.
