The 1954 MUTCD was published by the Bureau of Public Roads of the US Department of Commerce. This was a substantial revision to the 1948 edition, and served as the official edition of the MUTCD in the United States until the publication of the 1961 edition.
Notable Changes from the 1948 Edition
Yield Signs (Section 31.1)
The Yield sign was first introduced. It had a black legend "YIELD RIGHT OF WAY" on a yellow background. It was regarded as "experimental," and used "cautiously, and only where suitable legislation has been adopted to define its meaning and to authorize its use."