Route 83 will be closed for road construction, while Highway 175 will have two open lanes.
Parallelism is the repetition of the same grammatical structure. Many native English speakers use it automatically when listing things they did during the day. For example, yesterday I went running, swimming, and shopping. The verbs all ending in -ing gives them the same grammatical structure. In this sentence, each section (except for the conjunction) begins with the subject then the helping verb will, and is followed by the description. The other options do not have the same grammatical structure in the phrases before and after while.