The ministry of road transport and highways' (MoRTH's) initiative to let toll-road users pay only for the distance travelled should seem like a good idea. But MoRTH needs to ensure that the technological infrastructure that will go into this is fail-safe. The initiative, as per a Business Standard report, rests on what is called geo-fencing, or tracking through global positioning system or radio frequency identification (RFID). The National Highways Authority of India will be setting up toll plazas at every entry\/exit points on a toll road to ensure that vehicles are charged when a response is triggered by a mobile device on a vehicle entering or leaving the road. The initiative follows the government's move to have RFID-based FASTags\u2014at present, FASTags are operational on one lane on each side of 414 toll roads\u2014that will allow for seamless movement on highways and automatic payment of toll . The problem is while FASTags were made mandatory for new four-wheelers from December 1, 2017, and for all new vehicles from March 1, 2018, a great many number of older vehicles are yet to get these. At the moment, just 7.5 lakh vehicles have FASTags and a further 25 lakh are set to get these in the coming months, against many as 21 crore registered motor vehicles in the country. Moving to an automated, distance-travelled-based toll system is not going to prove easy. This is not to say that the government must not move in this direction. But it will remain a rather complicated system until all vehicles are RFID-GPS enabled. There will be regular lanes as well\u2014as there are now\u2014till the time all vehicles are RFID-GPS ready, but in a distance-travelled toll collection scenario, that will remain fraught with challenges, something that the government must give serious thought.