About FASTag :
FASTag is an electronic toll collection system in India, operated by the National Highway Authority of India. It employs Radio Frequency Identification technology for making toll payments directly from the prepaid or savings account linked to it or directly toll owner.
From 15 February 2021 FASTag is mandatory for 4 wheelers for making toll payments.
Pay Road Toll Payments Online – Go Cashless with FASTag – Hassle Free