When I was a youngster growing up in California (1950's-1960's) there were still sections of highways that used a middle "passing lane" that vehicles going in either direction could use when "available". Unfortunately, in 1937 I lost three relatives who died tragically in a head-on collision using that "passing lane" near Burlingame. California. This would have been my Aunt, her mother, and her brother. That highway design was eventually discontinued, but not soon enough if you ask me.