Train services on the Chennai-Arakkonam sector, which was halted after the train accident at Chitheri about 90 km from Chennai on Tuesday night, resumed on Wednesday evening.
The services were restored on Wednesday evening, official sources said.
Many trains were cancelled and some were diverted via Villupuram and other areas due to the mishap.
At least 10 people were killed and more than 50 injured when a speeding passenger train rammed into a stationary train at Chitheri, about 90 km from Chennai, derailing five coaches on Tuesday night.
The Chennai Beach-Vellore Cantonment Mainline Electrical Multiple Unit (MEMU) train crashed into the Arakkonam-Katpadi passenger from behind as it was waiting for signal around 9:40 p.m.