Bridges in Society

Effect of Bridges on Society
Bridges Over Time
10,000BC onwards primitive beam and suspension bridges have been used to transport people or objects across rivers or ravines. This primitive design may have consisted of a mere log between two banks, but it was the first of many bridge designs to come that would impact greatly on society. The first notable change in this design was when the greeks improved upon the beam bridge design, this allowed the bridges to be used more easily by humans or animals transport. Then next innovation was the roman arch bridge. This bridge brought a new arch design that increased security and stability and reduced the effect on water traffic of many early beam bridges. This allowed waterways to remain modes of transport but also improved transport across the bridge. The medieval age brought with it the medieval arch bridge with a decreased efficiency in design and greater invasion of water traffic than is predecessor. During the 16th the first truss design improved the beam bridge design, increasing its ability to span greater distances, less pylons required and greater safety. The Renaissance era brought with it a change within the arch bridge design reverting to a similar design as the Roman arch bridge, increasing clearance for water traffic. During the 19th century James Finlay designed the modern suspension bridge bringing longer spanning distances and reduced effect of waterways. Also the 19th century brought with it the bow-string girder or tied arch bridge which was inexpensive and simple in design and was suitable to railway transport. During the 20th century was constructed which was especially suited to freeway purposed bridges. The construction of these bridges greatly improved road transport and freight transport via roadways which in turn influenced the decline of railway transport. Also during the 20th century came the first modern balanced cantilever bridge which was efficient in construction with relation to...