Bridging the Hudson River was a difficult feat to accomplish, and although many architects had ambitions of linking Manhattan and New Jersey, none were as capable and ready for the challenge as Othmar Ammann, a Swiss-born architect who was destined to design many of New York's most vital connective structures. Othmar Ammann proposed the plan for the bridge in 1923, and was soon chosen by the Port Authority as the new chief engineer. The bridge would connect the neighborhoods of Fort Lee, New Jersey with Washington Heights in New York City. Construction on the George Washington Bridge began in October of 1927. The plan for the bridge was ambitious since the bridge would be able to carry two levels of rail or roadway. The George Washington Bridge is a suspension bridge. It is 3,500 feet lengthwise, twice as long as any previous suspension bridge of its time. The center span would be suspended between two steel towers, each 570 foot tall, with a clearance at high tide of 212 feet. The construction of the bridge took place in stages: the two towers were built first and put in place at each side of the Hudson River. Then a total of four cables, each measuring three yards in diameter, were crafted. Each cable, made up of 434 individual wires, was wrapped around the span of the bridge 61 times. In total the steel cables are 107,000 miles in length and weigh a total of 28,100 tons. The cables are wrapped around a strand-shoe at each end of the bridge, which in-turn is tethered to a bar located deep into the anchorage. The anchorage itself was very secure, since it consisted of 110,000 cubic yards of concrete weighing up to 260,000 tons.On the four cables spanning the bridge, steel suspenders were secured so that construction on the roadway could begin. When it was opened in 1931, the roadways were not entirely complete. For instance the two center lanes of the bridge were left unpaved until 1946. The reason for this was the fact that the annual traffic volume was easily supported by the original six lanes of the George Washington Bridge. However as cars became mass produced, and more and more traffic crossed the bridge, it became necessary to open up additional lanes. In 1962 the lower roadway was finally completed, increasing the bridges capacity by 75% by opening additional six lanes to traffic.