SPOKANE, Wash. -- Washington state is continuing to look at whether a pay-by-mile program will work.

Right now, the state is running a pilot program where participants are logging their miles. The idea is to have drivers pay for every mile driven as opposed to pay for each gallon of gas they use. On Monday, KREM 2 introduced you to a woman participating in the pilot program. Many people still have questions about the whole concept.

One person asked, "What about people buying gas in Washington but don't live in Washington?"

Reema Griffith, executive director of the Washington State Transportation Commission, said the gas tax would not necessarily go away right way. So for those out-of-state drivers they would still pay the tax at the pump. The DOT predicts it could be decades before the gas tax was totally eliminated.

“The whole point of this pilot program is to better understand these challenges,” said Griffith. “Not a perfect thing and not a done deal.”

Another person wanted to know what about people who travel a lot from different states.

The DOT actually has some drivers in the pilot program who commute to Portland, Oregon or North Idaho regularly. Griffith said the goal is to make sure drivers only pay for miles they drive in Washington. They are still looking at ways to make this work between states.

About 400 people in the pilot program are testing out a new phone app. The app would allow a driver to turn on and off GPS tracking. So when they drive into another state they can turn on that GPS tracking and have that information on record. In theory, they would not be charged for those miles.

There is also some concern from those who drive fuel efficient cars or hybrids. One woman said she would feel punished if the pay-by-mile were to move forward in coming years.

Griffith said those who drive fuel efficient cars would be paying more in taxes. But they are filling up less and would continue to save more at the pump. The majority of what drivers pay at the pump is to the oil companies.

Griffith said they stress this is just a pilot program and they are trying different methods and ideas out.

In August, all 2,000 participants will be able to choose different methods of recording their mileage.