i dont know but its strong
Steel is the most common, especially for suspension bridges. Concrete is used for lower bridges (and where little shifting will occur) because it is more resistant to the elements.
Arch bridges are most used in Canada and the united states
Cables .
on high ways where there are lots of supports
wood and hot metal
they are commonly used on highways and over rivers
Bridge towers are used in suspension bridges or cable stayed bridges. cables, what hold roadway, are fixed there.
tension :D
steel cable suspension
tension :D
Some say it is the suspension bridge, others say it is the arch bridge.
John Roebling