The Washington Transportation Commission is expected to vote later this year on a proposal to replace the gas tax with a pay-per-mile system.

The current Washington state gas tax per gallon is 49.4 cents. That’s well-over the federal excise tax of 18.4 cents per gallon for gasoline and 24.4 cents per gallon for diesel fuel. 

With more electric vehicles and hybrids on the roads, the state is concerned the gas tax eventually won’t be enough to keep building and maintaining roads and bridges in the future.

Washington state recently announced hybrid and electric car owners will start paying an annual $75 car tab fee to finance electric car charging stations.

RELATED: Washington state enacts $75 fee for hybrid, electric cars

The state began looking at pay-by-mile, also known RUC for Road Use Charges, in 2012.

“Our legislature each year has been directing this research making sure it’s feasible, and that it pencils, that there’s a financial case to be made,” says Reema Griffith, the State Transportation Commission’s Executive Director.

The latest round of research includes results of a 2,000 driver/taxpayer study of people around the state. In it, those who conducted the study found that 68% of drivers preferred a pay-by-mile system and 19% wanted to stick with the gas tax.

The study simulated the use of various pay-by-mile systems, but did not employ the use of real dollars. Pay-by-mile options involve using a plug that goes into the on-board diagnostic port, typically located under the steering wheel portion of the dash board, or by phone apps.

Other states in the west are moving in the pay-by-mile direction, at least on a voluntary or limited basis. Oregon’s OReGO system is voluntary and charges 1.7 cents per mile. What drivers pay in gas tax is credited back to their accounts. There’s an app for that. 

On January 1, 2020, Utah is expected to implement a pay-by-mile option focused on electrics and hybrids, which would give drivers the option of paying by mile, or paying a flat upfront fee.

Recommendations discussed at Tuesday’s commission meeting included how to implement, how to avoid tax avoidance, how to count miles driven out-of-state, and whether, in the end, a state official needs to put eyes on an odometer.

Accepted recommendations are expected to be forwarded up to Governor Jay Inslee and the Legislature to make the next move.

One thing working against full implementation are bonds, which are contractually tied to the gas taxes collected, that could put off implementation for 10 to 25 years.

RELATED: Washington's pay-per-mile tax proposal faces vote later this year

It seems like nothing gets people worked up like road taxes. 

As proof, Initiative 976 on next month’s ballot calls for voters to roll back taxes paid on car registration to $30. The issue is particularly acute with drivers covered by Sound Transit, where tab fees can run into hundreds of dollars every year to pay for light rail expansion and other transit upgrades.

RELATED: Seattle City Council rejects Tim Eyman’s $30 car-tab Initiative 976 to his face

In three weeks, tolls begin on the new tunnel under downtown Seattle, not to mention tolls on the SR 520 bridge, Tacoma Narrows and so called Hot HOV Lanes on 405 and 167.

RELATED: 5 things to know about Seattle tunnel tolling

Full report: Washington State Road Usage Charge