It wasn’t always the case that a motorist could kill pedestrians without penalty:
[A] 1923 editorial from the St. Louis Post-Dispatch […] opined that even in the case of a child darting out into traffic, a driver who disclaimed responsibility was committing “the perjury of a murderer.”
The [automobile] industry lobbied to change the law […] to restrict pedestrian use of the street and give primacy to cars. The idea of “jaywalking” – a concept that had not really existed prior to 1920 – was enshrined in law.
From: “The Invention of Jaywalking”, The Atlantic Cities
But, in fair Oregon, the law is on the side of the pedestrian. In short, jaywalking is not illegal in Oregon. That is, there are no statutes in Oregon that deem jaywalking illegal, and, as Ray Thomas put it:
What is not taken away is given.
That does not mean that you cannot get a traffic ticket as a pedestrian.