In 1930, German engineer Werner Ruchti was contracted to design the traffic circle, which was to be based on European models.

[1] The Los Alamitos Traffic Circle was one of the first of its kind to be constructed in the United States, and prior to their truncation, was also an end point of US 6 (which connects Provincetown, Massachusetts some 3,227 miles (5,193 km) to the east) and US 91.

PCH (the main thoroughfare) was given an additional entry lane at both north and south bound routes.

After the conversion, both the total auto accident and the injury rate significantly dropped, making the circle one of the safest statistically in the nation.

The artery Atherton Street ends at the Outer Traffic Circle and does not continue toward the main roundabout