Sentence:  And there are now many millions of workers for whom the factory with the big parking lot , which can be reached by driving across or against the usual pattern of rush hour <WSD>traffic</WSD> and grille route bus lines , is actually more convenient than the walk-to factory . 
Meaning of the word marked with <WSD> tags:  the aggregation of things (pedestrians or vehicles) coming and going in a particular locality during a specified period of time