The curve near the Tambaram Irumbuliyur railway bridge, which is the gateway to Chennai, is a two-lane road. It is there that people going to Bangalore and those going to Maduravoyal, Koyambedu, Porur, and Mudichur split. The road that runs along the river till Perungalathur becomes a two-lane road near the Irumbuliyur bridge after crossing the bridge. This is the main reason for the congestion.