This image shows the early form of the multi-lane highway as they were first built before the establishment of the Interstate system.
The description states:
A DESERT HIGHWAY
In sharp contrast to early-day travel, crossing the deserts of the west today on broad, smooth highways is an enjoyable experience.
–This highway is interesting to compare to current designs. This road has no median divider separating the opposite flows of traffic. Even more unusual is the dotted line in the center, indicating that it was permitted to cross into oncoming traffic to pass vehicles in the left lane in your direction. Both of these conventions were deemed too hazardous to maintain with the increase in traffic speed and frequency.
This image likely dates from the 1950s.