The area spanned by a suspension bridge is very long in proportion to the amount of materials required to construct bridges.
Built over waterways, suspension bridges can be built high, allowing the passage of tall ships unhindered by the bridge.
During construction, temporary central supports do not need to be built, and access to the construction is not required from beneath. This means busy roadways and waterways do not need to be disrupted.
The added flexibility of suspension bridges allows them to flex under the power of winds and earthquakes. But suspension bridges can be unstable in extremely turbulent conditions, with extreme cases requiring temporary closure of the bridge.
When built in soft ground, suspension bridges require extensive and expensive foundation work to combat the effects of the heavy load on foundation towers.
Flexibility can be a disadvantage to suspension bridges, which can flex under heavy, concentrated loads. Suspension bridges are not generally used for regional rail crossings that carry maximum weight loads, causing added stress on the bridge.
