加利福尼亚州帕洛阿尔托的洛克希德·马丁研究所的研究人员仅用18个月，就设计出一条复合材料制造的长140英尺（42．7米）的车辆承重桥，并进行了分析、制造、组装和检测。这种新型桥梁的研制正逢美国公路桥的维修和更新面临危机的时候。科学家们说，在美国各地，由于年久失修 In just 18 months, researchers at the Lockheed Martin Institute in Palo Alto, California, devised a 140-foot-long (42.7-meter) vehicle weight bearing bridge made of composite material and analyzed it, Manufacture, assemble and test. The development of this new type of bridge coincided with the time when the maintenance and renewal of the U.S. highway bridge was in crisis. Scientists say that throughout the United States, due to the disrepair