In 1921, the average traffic volume on the Pacific Highway east of Olympia was 1,929 vehicles, in 1924, it was 4,050, and in 1926, it was 7,891.
The average traffic volume south of Tumwater in 1921, was 1,058 vehicles, in 1924, it was 3,193, and in 1926, 6,237 cars, trucks, motorcycles and wagons traveled the road.
The Pacific Highway Evolves into 4 Lanes
In 1936, a new 4 lane highway was completed between Lacey and Tacoma.
From Lacey to the east side of the Nisqually river, this road is now known as Martin Way.
On the west side of the valley, the state had to dig out a deep cut in the hillside to give the road an easy grade down the hill. In 1938, south of Olympia, a new 4 lane highway was completed between Trosper Road and Capitol Way.
The Pacific Highway through downtown Olympia would remain 2 lanes.