It's actually not hard to fix.  I've knocked out far larger errors throughout PA/KY/TN in less than an hour.  In JOSM, you detach one way at the two ends (at Lynn and N Moorpark), delete the other way, slide the remaining one to centerline (CL) of roadway (most of the crossing nodes will follow correctly), delete the one-way key, fix the odd misplaced crossing nodes using the Improve Way Accuracy tool down the CL, re-attach the endpoints and post the changeset.  
There are OSM people who focus on this kind of thing hence I left a note, but if no one picks it up soon, I'll fix it.  When Janss is corrected, then the correct lane assignments can be applied, which it pretty important since this is main route to the only hospital in T.O. - I know from sad personal experience.  I am currently working elsewhere up and down the Conejo Valley - it's not in great shape - few addresses, many of the ones that exist use abbreviations or lack the full way name (which breaks routing), whole neighborhoods missing buildings and addresses, streets spelled per the original Tiger import, not per local T.O and County of Ventura GIS.  When I'm done trying to make a dent in some of this, I will come back and resolve the Janss issue if no one else does. 