KOCHI: Passenger and express trains began to ply along the doubled Ernakulam-Mulanthuruthy route on Saturday, after the Railways completed the doubling works on the 18-km route. Goods trains will ply later. Since some overhead-line work was pending at Tripunithura, some south-bound trains from Ernakulam through Kottayam were routed through Alappuzha. But north-bound trains through Kottayam plied as usual. A few trains were delayed. Normal traffic through the Kottayam route will resume on Sunday. The delay in completing doubling works had thrown traffic along the route had gone in the last two days.