  The classical Hall effect, the traditional means of determining
charge-carrier sign and density in a conductor, requires a magnetic field to
produce transverse voltages across a current-carrying wire. We show that along
curved paths -- $\mathrm{\textit{without}}$ any magnetic field -- geometry
alone can produce nonlinear transverse potentials that reflect the
charge-carrier sign and density. We demonstrate this effect in curved graphene
wires where the transverse potentials are consistent with the doping and change
polarity as we switch the carrier sign. In straight wires, we measure
transverse potential fluctuations with random polarity demonstrating that the
current follows a complex, tortuous path. This geometrically-induced potential
offers a sensitive characterization of inhomogeneous current flow in thin
films.
