Foothill Extension corridor
E390084
The Foothill Extension corridor is a segment of Los Angeles County’s light rail network that extends service eastward through the San Gabriel Valley, connecting additional suburban communities to the regional Metro Rail system.
All labels observed (2)
| Label | Occurrences |
|---|---|
| Foothill Extension | 1 |
| Foothill Extension corridor canonical | 1 |
How this entity was disambiguated
This entity first appeared as the object of triple T3804323 — resolving that mention is where its identity was fixed. The disambiguator weighed these candidate entities and picked the highlighted one (or “None”, minting a new entity). This is how homonymy is resolved: the same surface form can point to different entities.
NED1
Entity disambiguation (via context triple)
gpt-5-mini-2025-08-07
Target entity: Foothill Extension corridor Context triple: [L Line (Los Angeles Metro), servedCorridor, Foothill Extension corridor]
-
A.
Foothill Freeway
The Foothill Freeway is a major east–west freeway in Southern California that runs along the base of the San Gabriel Mountains, serving as a key commuter and regional connector.
-
B.
Banfield Freeway corridor
The Banfield Freeway corridor is a major transportation route in Portland, Oregon, carrying Interstate 84 and associated rail and transit lines through the city’s east side.
-
C.
Alameda Corridor
The Alameda Corridor is a 20-mile freight rail expressway in Los Angeles County that consolidates and streamlines cargo movement between the region’s ports and the national rail network.
-
D.
Arroyo Seco Parkway
Arroyo Seco Parkway is a historic early freeway in Southern California, recognized as one of the first modern highways in the United States and a key connector between Los Angeles and Pasadena.
-
E.
H-3 Freeway
H-3 Freeway is a major interstate highway on the island of Oʻahu in Hawaii that traverses the Koʻolau Range to connect Honolulu’s leeward side with the windward communities, including Kailua.
- F. None of above. chosen
- G. Unsure - the case is ambiguous/there is not enough information to decide.
NED2
Entity disambiguation (via description)
gpt-5-mini-2025-08-07
Target entity: Foothill Extension corridor Target entity description: The Foothill Extension corridor is a segment of Los Angeles County’s light rail network that extends service eastward through the San Gabriel Valley, connecting additional suburban communities to the regional Metro Rail system.
-
A.
Foothill Freeway
The Foothill Freeway is a major east–west freeway in Southern California that runs along the base of the San Gabriel Mountains, serving as a key commuter and regional connector.
-
B.
Banfield Freeway corridor
The Banfield Freeway corridor is a major transportation route in Portland, Oregon, carrying Interstate 84 and associated rail and transit lines through the city’s east side.
-
C.
Alameda Corridor
The Alameda Corridor is a 20-mile freight rail expressway in Los Angeles County that consolidates and streamlines cargo movement between the region’s ports and the national rail network.
-
D.
Arroyo Seco Parkway
Arroyo Seco Parkway is a historic early freeway in Southern California, recognized as one of the first modern highways in the United States and a key connector between Los Angeles and Pasadena.
-
E.
H-3 Freeway
H-3 Freeway is a major interstate highway on the island of Oʻahu in Hawaii that traverses the Koʻolau Range to connect Honolulu’s leeward side with the windward communities, including Kailua.
- F. None of above. chosen
Statements (24)
| Predicate | Object |
|---|---|
| instanceOf |
light rail corridor
ⓘ
public transportation infrastructure ⓘ |
| alsoKnownAs |
Foothill Extension corridor
ⓘ
surface form:
Foothill Extension
|
| category |
Light rail in California
ⓘ
Public transport in Los Angeles County ⓘ |
| connects | suburban communities in the San Gabriel Valley ⓘ |
| connectsTo |
Los Angeles Metro Rail
ⓘ
surface form:
Los Angeles Metro Rail network
|
| country |
United States of America
ⓘ
surface form:
United States
|
| hasFunction |
regional connectivity
ⓘ
suburban transit access ⓘ |
| infrastructureType | rail transit corridor ⓘ |
| locatedIn |
California, United States
ⓘ
surface form:
California
Los Angeles County ⓘ United States of America ⓘ
surface form:
United States
|
| networkRole | eastward extension of Metro Rail service ⓘ |
| operator | Los Angeles County Metropolitan Transportation Authority ⓘ |
| partOf |
Los Angeles Metro Rail
ⓘ
surface form:
Los Angeles County Metro Rail system
Los Angeles Metro Rail ⓘ
surface form:
Los Angeles County light rail network
|
| purpose |
to connect additional suburban communities to the regional Metro Rail system
ⓘ
to extend light rail service eastward through the San Gabriel Valley ⓘ |
| regionServed | eastern Los Angeles County ⓘ |
| servesRegion | San Gabriel Valley ⓘ |
| systemType | urban rail transit ⓘ |
| transportMode | light rail ⓘ |
How these facts were elicited
The pipeline generated the facts above by prompting gpt-5.1 with this entity's name + description and the instruction below.
Instruction
You are a knowledge base construction expert. Given a subject entity and a description of it, return factual statements that you know for the subject as a JSON list of dictionaries(triples), where keys must be "subject", "predicate" and "object". The number of facts may be very high, between 25 to 50 or more, for very popular subjects. For less popular subjects, the number of facts can be very low, like 5 or 10. # Requirements - If you don't know the subject at all, return an empty list. - If the subject is not a named entity, return an empty list. - Include at least one triple where predicate is "instanceOf". - Do not get too wordy. - Separate several objects into multiple triples with one object.
Input
Subject: Foothill Extension corridor Description of subject: The Foothill Extension corridor is a segment of Los Angeles County’s light rail network that extends service eastward through the San Gabriel Valley, connecting additional suburban communities to the regional Metro Rail system.
Referenced by (2)
Full triples — surface form annotated when it differs from this entity's canonical label.
subject surface form:
L Line (Los Angeles Metro)
this entity surface form:
Foothill Extension