At the same time Nevada and Arizona began looking at US 93 's crossing of Hoover Dam , a major bottleneck for regional commerce , with hairpin turns , multiple crosswalks for pedestrians and steep grades . Plans for a bridge to bypass the dam became even more urgent when the road was closed to trucks after 9/11 in 2001 , forcing commercial traffic to detour through Bullhead City , Arizona and Laughlin , Nevada , causing major transport delays as a result
9/11
September 11 attacks
Interstate 11