This is the 1540th most frequent Swedish word.
regionala
"Regionala" means "regional" in English.
Here 'regionala' is used as an adjective modifying 'skillnaderna' (differences), denoting that the differences pertain to particular regions.
De regionala skillnaderna i dialekt är fascinerande.
The regional differences in dialect are fascinating.
In this sentence, 'regionala' acts as an adjective describing 'infrastrukturen' (infrastructure), indicating that the infrastructure improvements focus on specific regions.
Vi planerar att förbättra den regionala infrastrukturen.
We are planning to improve the regional infrastructure.
Here, 'regionala' qualifies 'tjänster' (services), showing that these services are restricted or specific to certain regions.