  We study the asymptotic behaviour of the quantum representations of the
modular group in the large level limit. We prove that each element of the
modular group acts as a Fourier integral operator. This provides a link between
the classical and quantum Chern-Simons theories for the torus. From this result
we deduce the known asymptotic expansion of the Witten-Reshetikhin-Turaev
invariants of the torus bundles with hyperbolic monodromy.
