Bridges have always been something that many civilizations have had trouble with. What with the bridges having being able to withstand weather, floods, and also being strong enough to hold up to travelers and an army. The Romans were given the credit of having the “first and longest lasting bridges built” (Wikipedia) in first and second century AD. As shown in the below picture, the Romans are able to put a lot of weight on their bridges that are even still up today.
Before the Romans many of the past civilizations had been trying to a form of cement, which the Romans used as well, but they were the ones who had thought of making arches which opened up a whole new world of bridge making. The Romans got much of their engineering from the Etruscans and also the Persians (Jays History) but learning to use a keystone arch for their bridges had been a new thought process entirely. It was during the reign of Trajan, a Roman emperor, that the new design of bridges were built. “Some of the most impressive Roman bridges are over ravines. A fine surviving example, built for Trajan in AD 105, spans the Tagus in Spain, at Alcántara. Its two massive central arches, 110 feet wide and 210 feet above the normal level of the river, are made of uncemented granite. Each wedge-shaped block weighs 8 tons.” (History net)
The bridges that were created essentially had made traveling and new towns because people could have easier access. “Allowing the river to be crossed at any time of the year, the bridge was an important factor of development for the town, but it was also necessary and useful for the Pax Romana: here there were hot springs visited by a lot of people; in the region there were mines with precious metals, whose product was taken to Rome; across the bridge passed the important Roman road of Braga to Astorga, with a lot of traffic; and lastly here was quartered a numerous detachment of legionnaires of the Roman army.” (Wikipedia)
The bridges that the Romans had created were the first steps into making the idea of a unified world. Not to mention that bridges have changed the architecture of everything. The picture of the bridge in the Trajan’s column shows how much without the bridges, the Romans couldn’t get across the Danube, and it has changed the outcome of the world. (Peter Rockwell, STOA)
Rockwell, P. Bridge. Retrieved March 8, 2012 from http://www.stoa.org/trajan/buildtrajanpage.cgi?260