With no political valor to raise the federal gas tax, some are looking towards a replacement tax that is based on how many miles a vehicle traveled. Technology has sufficiently advanced to the point where innocuous “black boxes” can be installed in cars to record such information, so that relevant agencies can charge the user accordingly. Agencies can further charge drivers according to the weight of their vehicles if they so choose. However, privacy remains the main issue as to why the concept has not been implemented, as this letter to the editor made clear. Some are concerned that if the technology is GPS-based, law enforcement agencies could track vehicle movements instantly. Also, the notion of a vehicle-miles-based tax may very well betray the notion that transportation facilities benefit “the broad public interest” in a myriad of ways, even if some people do not directly use such facilities.