1953 Puerto Rico highway renumbering

Highways in P.R. August 1928
System information
Formed	1953
Highway names
Pre-Commonwealth:	Insular Highway nn (Hwy nn)
Post-Commonwealth:	Puerto Rico Highway nn (PR-nn)
System links
Roads in Puerto Rico List

In 1953, the Puerto Rico Department of Transportation and Public Works implemented a major renumbering of its insular highways.^[1] Before 1953, highway routes were numbered in the 1 to just over 100 range and were distributed randomly throughout the island, resulting in several routes with long road lengths.^[2] The numbering system adopted in 1953, which is in use today, increased the range of route numbers from the just-over-100 to 999, resulting in a decrease in the length of many routes.^[3] This new numbering system follows a grid pattern for highways numbered between 100 and 999, with the lower numbered roads found to the west and systematically increasing towards 999 as the traveler moves easterly. Although PR-1, PR-2 and PR-3 routes had notable changes in some of their segments, these three are the only highways that kept their route numbers intact due to their interregional prominence.^[4]