I was a lady traveling alone to chidambaram for the first time from ernakulam. It's not at all safe for a lady to travel alone. There were very few passengers, all males, no families or ladies. And this bus takes the most longest route to chidambaram, via Velankanni, with a bus change at karaikal.
In between the bus staff were stopping at popular bus stops around here and letting public in for drop en route for a charge. I felt, traveling by ksrtc or Tamil Nadu state bus would be safer and got down before thrichur and cancelled my journey for my own safety.
I was(around until two years back) a regular bus traveler to Bangalore and mangalore. I have never experienced such a thing.