Final answer:
Policymakers expected increased competition and lower shipping costs, as well as a rise in safety standards, when they deregulated the trucking industry.
Step-by-step explanation:
When policymakers deregulated the trucking industry, they expected increased competition leading to lower shipping costs and a rise in safety standards due to market forces. Deregulation removed government restrictions on the firms that could enter the industry, the prices they could charge, and the quantities they could produce. This allowed for more competition among trucking companies, which in turn led to lower shipping costs as companies competed for business. Additionally, with the market forces at play, trucking companies had an incentive to prioritize safety standards to attract customers and maintain their reputation.