A Federal pre-emption controls if there is a conflict between an Oregon law and a Federal law.   Not all Federal laws "pre-empt" local and State laws.  

Railroad operations, commercial airplane operations,  seat belt requirements do. 

"This Constitution, and the laws of the United States which shall be made in pursuance thereof; and all treaties made, or which shall be made, under the authority of the United States, shall be the supreme law of the land; and the judges in every state shall be bound thereby, anything in the Constitution or laws of any State to the contrary notwithstanding."

"As the Supreme Court stated in Altria Group v. Good, 555 U.S. 70 (2008), a federal law that conflicts with a state law will trump, or "preempt", that state law:
"Consistent with that command, we have long recognized that state laws that conflict with federal law are "without effect." Maryland v. Louisiana, 451 U. S. 725, 746 (1981)"

https://en.wikipedia.org/wiki/Federal_preemption