When do you need a bridge designer ?

One of the jobs I am presently involved with is the replacement of the main drive arrangement in a lift bridge. This job underscores the importance of maintaining civil engineering infrastructure items like bridges. I've posted some pictures on my bridge designer page. Even though most bridges look like they are built to last 100 years its surprising how often they need repair. Especially when you have the corrosive action of road salt, ice and snow to contend with.