Puerto Rico Highway 3(PR-3) at nearly 100 miles long, is the second longest highway on Puerto Rico. It connects the San Juan neighborhood of Río Piedras to downtown Salinas indirectly around the eastern coast of the island. Highway 3 ranges from a three lane urban avenue in San Juan to a one lane rural road past Fajardo. While other roads connect San Juan, it runs the coastline of Puerto Rico east of San Juan, beginning in Río Piedras near Santurce and goes to Fajardo where it goes south paralleling the coastline to Humacao and Maunabo. It goes up to a mountain-scenic route and goes west to Salinas, where it meets PR-1.
Puerto Rico Highway 53 (PR-53) or unsigned Interstate PR3 is a main tollway that is parallel to Puerto Rico Highway 3, which goes from Fajardo to Salinas. Some segments are still in planning, but when finished it will be about 58 miles (93 km) in length. Two tunnels, about 0.6 mi (1 km) long each, in the towns of Yabucoa and Maunabo were completed in October 2008. It will connect the cities of Fajardo, Ceiba, Naguabo, Humacao, Yabucoa, Maunabo, Patillas, Arroyo, Guayama and Salinas, thus bordering the entire eastern and southeastern coasts of Puerto Rico. Its northern terminus is at PR-3 and PR-194 in Fajardo, and its south terminus is at PR-52 in Salinas.
Puerto Rico Highway 66 (PR-66) is a main tollway which parallels Puerto Rico Highway 3 going from the city of Carolina, Puerto Rico via a 3 loops cloverleaf interchange with PR-26 and PR-3, a major exit in the form of a Trumpet interchange in Canóvanas, Puerto Rico and ending in the municipality of Río Grande, Puerto Rico with an intersection of PR-3. It is only 19.5 kilometres (12.1 mi) long and has very few exits, which work mainly to minimize traffic in the congested Carolina area of PR-3.
Puerto Rico Highway 111 (PR-111) is a highway connecting Aguadilla, Puerto Rico at Puerto Rico Highway 2 and Puerto Rico Highway 115 to Utuado, Puerto Rico at Puerto Rico Highway 140.
Puerto Rico Highway 116 (PR-116) is a main highway in the southwest part of Puerto Rico, beginning in Guánica, Puerto Rico at Puerto Rico Highway 2 to Lajas, Puerto Rico at Puerto Rico Highway 101.
Puerto Rico Highway 344 (PR-344) is a rural road in Hormigueros, Puerto Rico, beginning from near the municipality's small downtown and ending at PR-348 near the border with San Germán in barrio Rosario. It has narrow lanes, and after about five kilometers becomes one of the most dangerous highways in Puerto Rico, as it goes near a precipice with little or no safety barriers. It serves as a route to Mayagüez via PR-348 which ends in Puerto Rico Alt Route 2.
Puerto Rico Highway 185 (PR-185) is a main highway that connects Canóvanas, Puerto Rico to Juncos, Puerto Rico and is about 25 kilometers long. It begins in downtown of Canóvanas, very close to Puerto Rico Highway 3 and ends in Puerto Rico Highway 952 and Puerto Rico Highway 30 in Juncos. For people coming from/going to Caguas, the highway has a direct intersection with PR-30; for those coming from/going to Humacao, drivers have to take short highway PR-952 and then take PR-189 just before its intersection with PR-30, hence this exit being one of the most disorganized junctions in the island between a main highway and a main freeway or tollway in the island. New Puerto Rico Highway 66 also has a poor-designed intersection with the highway, since it only allow people going to/coming from Carolina (west) and not the east. This is probably because the short segment open from the new tollway immediately ends at PR-3 only 2 kilometers from the exit to PR-185 and thus expected to be fixed when the segment to Río Grande opens to the public.
Puerto Rico Highway 165 (PR-165) is the road that goes from Naranjito to Guaynabo. The highway passes by Toa Alta, Toa Baja, Dorado, Levittown, Cataño and Guaynabo.
Puerto Rico Highway 500 (PR-500) is a tertiary road in Ponce, Puerto Rico. The highway has both of its endpoints, as well as all of its length, entirely within the Ponce city limits. It runs east to west.
Puerto Rico Highway 139 (PR-139) is a two-way secondary highway in the municipality of Ponce, Puerto Rico.
Puerto Rico Highway 502 (PR-502) is a tertiary state highway in Ponce, Puerto Rico. The road runs north to south through barrio Quebrada Limón. Its southern terminus is at an intersection with PR-132. Its northern terminus is at its intersection with PR-501.
Puerto Rico Highway 939 (PR-939) is a road located in Maunabo, Puerto Rico. This highway extends from PR-760 in downtown Maunabo to Quebrada Arenas.
Puerto Rico Highway 693 (PR-693) is a road located between the municipalities of Dorado, Puerto Rico and Vega Alta, passing through downtown Dorado. It begins at its intersection with PR-2 and PR-165 in Río Lajas and ends at PR-690 in Sabana. It is a short divided highway in southern Dorado, which serves as an alternate route for PR-165 west of Río de la Plata.
Puerto Rico Highway 760 (PR-760) is a rural road located in Maunabo, Puerto Rico. It begins at its intersection with PR-3 near downtown Maunabo and ends at Punta Tuna Light.
Puerto Rico Highway 110 (PR-110) is a road that goes from Añasco, Puerto Rico to Aguadilla through Moca. It extends from Puerto Rico Highway 2 north of Añasco to Ramey Air Force Base.
Puerto Rico Highway 108 (PR-108) is a road that travels from Mayagüez, Puerto Rico to Añasco. It begins at its intersection with PR-105 in downtown Mayagüez and ends at its junction with PR-109 in eastern Añasco, near Las Marías and San Sebastián. Near this road is located the Mayagüez Zoo.
Puerto Rico Highway 190 (PR-190) is a road located in Carolina, Puerto Rico. This highway begins at its intersection with PR-26 in Cangrejo Arriba and ends at its junction with PR-3 and PR-8887 between Sabana Abajo and San Antón barrios.
Puerto Rico Highway 200 (PR-200) is a road located in Vieques, Puerto Rico. This highway extends from Mosquito to Puerto Diablo, passing through Isabel II.
Puerto Rico Highway 195 (PR-195) is a road located in Fajardo, Puerto Rico, passing through its downtown. This highway begins at PR-3 west of downtown Fajardo and ends at the Port of Fajardo.
Puerto Rico Highway 187 (PR-187) is a road that travels from Río Grande, Puerto Rico to Carolina, passing through Loíza. This highway begins at its intersection with PR-3 and PR-66 in Guzmán Abajo and ends at PR-26 in Isla Verde.
PR-3 in Quebrada Vueltas 
PR-3 / PR-940 in Quebrada Fajardo
