US Bridges

Pr 18 Southbound over Pr 21

Fair

San Juan Municipio, Puerto Rico · 5.8 KM N E of Guaynabo · Structure no. 009592

Built
1965
60 years old, rebuilt 1999
Condition
Fair
inspected September 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
252 ft
4 main spans
Daily traffic
84,550
2017 count
Owner
State
State Highway Agency

About this bridge

Pr 18 Southbound over Pr 21 is a prestressed concrete stringer/multi-beam or girder carrying Pr 18 Southbound over Pr 21 in San Juan Municipio, Puerto Rico. It was built in 1965 and reconstructed in 1999, so it is 60 years old, older than the Puerto Rico average of 51.2 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 84,550 vehicles a day, roughly 7% of them trucks, projected to reach 96,400 by 2025. The structure is 252 ft (76.7 m) long and 93 ft wide. If it were closed, the detour would be 0.6 mi (1 km).

Location

Open in Google Maps
CarriesPr 18 Southbound
CrossesPr 21
Location5.8 KM N E of Guaynabo
RouteInterstate 18
CountySan Juan Municipio
StatePuerto Rico
Coordinates18.38955, -66.07213
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionSeptember 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating62.3 US tons
Inventory rating32.1 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20
Structure length252 ft (76.7 m)
Longest span84 ft (25.6 m)
Deck width93 ft (28.4 m)
Roadway width74 ft (22.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic84,550 (2017)
Projected traffic96,400 by 2025
Trucks7%
Lanes on structure5
Traffic directionOne-lane bridge for two-way traffic
CarriesHighway
CrossesHighway
Detour if closed0.6 mi (1 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$555,000 (2017 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was Pr 18 Southbound over Pr 21 built?

It was built in 1965, making it 60 years old in 2025. It was reconstructed in 1999.

What condition is Pr 18 Southbound over Pr 21 in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in September 2023.

How much traffic does Pr 18 Southbound over Pr 21 carry?

About 84,550 vehicles per day (2017 count), of which roughly 7% are trucks.

How long is Pr 18 Southbound over Pr 21?

The structure is 252 ft (76.7 m) long with a longest span of 84 ft (25.6 m) and a deck 93 ft wide.

Who owns Pr 18 Southbound over Pr 21?

It is owned by the State Highway Agency.