George Miliken road spans between US20 just west of Brothers to Prineville on US26. It is a good bypass if you want to avoid Bend. (which I highly suggest)
I have no experience with this road, but generally any paved road with center stripes and fog lines in central Oregon is fine.
Zooming in tight with satellite views shows it to be a good road. I see an 18 wheeler on the road via satellite.
I wouldn't hesitate to take it!