From Turin or the Frejus tunnel: take the Oulx Circonvallazione exit from the A32 Turin-Bardonecchia, then continue in the direction of Sestriere-Monginevro on the SS24 as far as Cesana Torinese.
From France Colle di Monginevro SS24
From Pinerolo Col del Sestriere SS24 and SP23