This is the 2787th most frequent Polish word.
handlowej
"Handlowej" means "commercial" or "trade" (genitive or dative form of "handlowa").
Here, 'handlowe' modifies 'centrum', indicating it is a commercial center.
Odwiedziłem centrum handlowe.
I visited the shopping mall.
In this sentence, 'handlowa' describes the strategy, emphasizing its relationship to commerce.
Strategia handlowa firmy okazała się skuteczna.
The company's commercial strategy turned out to be effective.
'Handlowej' is an adjective in the locative case agreeing with 'ulicy', describing the type of street.