The new revenue would help finance the Highway Trust Fund, which currently depends mostly on fuel taxes to support roads and mass transit across the country. Under the proposal, the government would collect information about the miles that drivers travel from smartphone apps, another on-board device, automakers, insurance companies, gas stations, or other means. For now, the initiative would only be a test effort -- the government would solicit volunteers who drive commercial and passenger vehicles -- but the idea still raises concerns about the government tracking people's confidential data.

The bill would establish an advisory board to guide the programme that would include officials representing state transportation departments and the trucking industry as well as data security and consumer privacy experts. As the four-year pilot initiative goes on, the Transportation and Treasury departments would also have to keep Congress informed of how they maintain volunteers' privacy and how the per-mile fee idea could affect low-income drivers. Still, [Sean Vitka, policy counsel at Demand Progress] said the concept could put Americans' private data at risk. "We already know the government is unable to keep data like this secure, which is another reason why the government maintaining a giant database of travel information about people in the United States is a bad idea."