Key facts
Code summary
Code 421
Official title Construction of roads and railways
Version PSIC 2019
Source layer PSA / BSP
Parent 42 - Civil Engineering
Section F - Construction
Cn
PSIC 2019 Navigation-first hub Group 421 - Construction of roads and railways
PSIC Group 421 covers Construction of roads and railways. Direct children below it include Construction of roads and railways. It clusters closely related activities and helps compare nearby classes before choosing the...
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Nearby codes
About this level
Practical summary
Group 421 sits in the PSIC 2019 hierarchy under F Construction > 42 Civil Engineering. This group usually narrows the choice to a small family of classes such as Construction of roads and railways. It is useful when two or three neighboring activities look similar but should not be collapsed into one code.
Administrative context
Where this code is used
This group is used when reviewers compare a short list of classes such as Construction of roads and railways and need to decide which family is the closest fit. It is common in internal classification review and administrative lookup work.
Selection note
How to choose it
Use this group when the activity sits between similar classes such as Construction of roads and railways. The safest choice is the one whose wording matches the actual production, service or operating model most closely.
FAQ
What does PSIC Group 421 cover?
PSIC Group 421 clusters a smaller family of classes under Construction of roads and railways and is useful when the business sits between closely related options.
How do I compare Group 421 with sibling groups?
Look at the parent class and the nearby sibling groups. On this page, the most relevant nearby options are 422 Construction of utility projects and 429 Construction of other Civil Engineering Projects.
Why is Group 421 useful for classification?
It sits at the point where a broad sector is already narrowed enough to compare a small family of similar classes before the final code choice.