Complex sentence: Ross gave Wilshire various "firsts," including dedicated left-turn lanes and the first timed traffic lights in the United States; he also required merchants to provide automobile parking lots, all to aid traffic flow.
Split into simpler sentences: Ross gave Wilshire various "firsts," including dedicated left-turn lanes and timed traffic lights, the first in the United States. He also required merchants to provide automobile parking lots, all to aid traffic flow.