求翻译：Due to transportation's importance to economic growth, governments believed that carriers needed to be regulated to ensure service availability and stability. Availability meaning that carrier services would be accessible to all business enterprises. Stability meaning that carriers would be guaranteed sufficient profits to ensure viable long-term operation. Economic regulation generally sought to achieve its goals by controlling entry, rates, and services. In addition, economic regulatory practice treated each method of transport independently. This practice limited carrier ability to develop intermodal relationships and offerings. By 1970, federal economic regulation had reached the point where it affected 100percent of rail and air ton-miles, 80 percent of pipeline, 43.1 percent of trucking, and 6.7 percent of domestic water carriers. The degree of direct government economic regulation began to decline during the 1970s and took a dramatic turn in 1980 with the passage of major deregulatory legislation. The contemporary economic regulatory environment is dominated by free market competition more or less regulated by antitrust laws.是什么意思？

待解决 悬赏分：1 - 离问题结束还有