Respected sir/madam,
There are no bus (Route No 597) available from T. Nagar to Thiruvallur after 8 pm. But from Thiruvallur to T. Hagar last bus is started around 10 pm. After 10 pm there are so many buses running to various places in Chennai. These are running without even single passenger. Please run more the bus from various places in Chennai to Thiruvallur. Similarly run more buses from Thiruvallur to Chennai in the morning.