Uber is testing its own self-driving vehicle on the streets of  Pittsburgh, and the company said in a blog post that it's confident autonomous driving technology will positively impact the world of transportation.

"In the future we believe this technology will mean less congestion, more affordable and accessible transportation, and far fewer lives lost in car accidents," read Uber's post announcing the tests.

But one Oregon congressman is a little more skeptical, and thinks makers of autonomous vehicles should put some thought into how their creations impact tax revenue from transportation-related sources before the technology becomes commonplace.

Writing in Wired, U.S. Representative Earl Blumenauer said autonomous vehicle makers should incorporate data-tracking technology into the cars that would support a new means of taxing vehicle use other than the federal gas tax, a revenue source that has lost value precipitously over the past two decades:

"For the last 15 years, Oregon has been exploring a replacement to the gas tax based on vehicle miles traveled, a more accurate and fairer way to make sure drivers pay for the roads they enjoy. In the Oregon pilot project, a volunteer plugs a device into their vehicle that records miles driven and fuel consumed, and is sent an invoice or a refund depending on the state gas tax already paid at the pump.

That same data collection, reporting, and debiting could come standard in new cars tomorrow, providing a payment platform that could be used to pay for insurance, parking, existing tolls, and other location-based services. Integration of this miles traveled charge into market-ready and emerging vehicle technology can provide data to drive transportation planning decisions."

Widespread use of electric autonomous vehicles could render parking fees, traffic tickets and gas taxes virtually obsolete, he says. This means that companies like Google, Apple, Uber and others planning entry into the world of self-driving cars have a role to play in what comes next to replace those revenue sources.

Blumenauer's concern about government revenue from transportation sources compounds other worries about changes to transportation in general. Uber's entry into the self-driving vehicle realm, for example, has also raised a labor issue: Uber drivers may lose jobs as they are replaced with technology.

The congressman says of the coinciding emergence of self-driving vehicles and rise in popularity of ride-sharing services like Uber and Lyft, "I've never seen a combination of technological changes converge with this level of speed and intensity before."