Yup, cut it up, often way too long, bridge it and layer it. JOSM is not so ‘crossing ways’ validatirish. Done many country tracks crossing streams and bridge and never a squeal.
Few days ago came acrossing 2 tunnels, layer=0 and layer=1 tagged. Well that old rail tunnel is still not at the surface, the ceiling has not caved. Came across a town where the various went as low as -5 and -6. Think ID in general is good at 'who’s higher, lower and suddenly the driveway is in a tunnel, but back on OT, this is as tunnel=culvert as tunnel=culvert can be, with an incline it appears.