Most bridges are utilitarian in appearance, but in some cases, the appearance of the bridge can have great importance. Often, this is the case with a large bridge that serves as an entrance to a city, ...
Bridges can be categorized in several different ways. Common categories include the type of structural elements used, by what they carry, whether they are fixed or movable, and by the materials used.S ...
The first bridges were made by nature itself — as simple as a log fallen across a stream or stones in the river. The first bridges made by humans were probably spans of cut wooden logs or planks and ...
The Oxford English Dictionary traces the origin of the word bridge to an Old English word brycg, of the same meaning, derived from the hypothetical Proto-Germanic root brugjō. There are cognates in o ...
A bridge is a structure built to span physical obstacles such as a body of water, valley, or road, for the purpose of providing passage over the obstacle. There are many different designs that all ser ...
The United States has the largest network of roads of any country with 4,050,717 miles (6,518,997 km) as of 2009. The People's Republic of China is second with 3,583,715 kilometres (2,226,817 mi) of r ...
Main article: Transport economicsA city street in Mumbai, India with left-hand traffic.Transport economics is used to understand both the relationship between the transport system and the wider econom ...
Right- and left-hand traffic__Main article: Right- and left-hand trafficTraffic flows on the right or on the left side of the road depending on the country. In countries where traffic flows on the rig ...
Alignment — the route of the road, defined as a series of horizontal tangents and curves.Adverse camber — where a road slopes towards the outside of a bend, increasing the likelihood that vehicles t ...
Main article: Environmental impacts of roadsAir pollution along Pasadena Highway in Los Angeles, CaliforniaCareful design and construction of a road can reduce any negative environmental impacts.Water ...
Careful design and construction of roads can increase road traffic safety and reduce the harm (deaths, injuries, and property damage) on the highway system from traffic collisions.On neighborhood road ...
Like all structures, roads deteriorate over time. Deterioration is primarily due to accumulated damage from vehicles, however environmental effects such as frost heaves, thermal cracking and oxidation ...
Road construction requires the creation of a continuous right-of-way, overcoming geographic obstacles and having grades low enough to permit vehicle or foot travel. (pg15) and may be required to meet ...
The subject of road design is considered part of highway engineering. Structural road design is the science of designing a road for its environment in order to extend its longevity and reduce maintena ...
Main article: History of road transportThe assertion that the first pathways were the trails made by animals has not been universally accepted, since in many cases animals do not follow constant paths ...
