e. Building infrastructure

Related to all structures intended for industry requirements, business community, energy operations and living places.

i. *Industry and business:* Structures used for industry and business operation purposes. Examples include a single or multiple story structures and may be used as offices, machinery, equipment and industrial process.

a. A person who lives in the city can visualize the bridge as a simple access to schools, parks and theaters, or a simple way to visit a family member.

b. An engineer or architect visualizes the bridge as a way to connect the road

c. From the business community, the bridge can be viewed as access to different

Depending on the needs of the society to have a bridge, it would be its importance. A bridge that serves as a quick link to recreational parks with a low traffic flow will have less impact than a bridge crossing a large river and connecting two

Taking into account the sentence above, we can realize that bridges are not

i. Bridges must comply with traffic flow needs during its life period.

ii. Bridges must comply with required loads during its life period.

i. Bridges represent a high percentage of road's budget.

distance, the bridges are very expensive compared to the highway.

ii. High cost variability for different bridge geometries.

i. If the bridge has a failure, the road system fails.

If a bridge has a small number of lanes, narrow sizes or poor spaces, the struc-

This means that the analysis and structural design must take into account all the loads that the bridge must support. For example, if the structure is located on an interstate highway and was not designed to support heavy truck loads, it will have limited vehicle traffic and those trucks will not be able to use the bridge; therefore,

If we analyze the construction process of a road and measure the cost per unit

Depending on the number of lanes required, types of vehicles to be supported, distances and/or clear span to cover, materials and available labor, the cost of the bridges are variable. Proper planning is required to meet the needs and comply with

If we analyze the entire road and at specific place, one of the bridges does not work, the vehicular flow will be affected, increasing traffic flow, delays, time lost

built arbitrarily; a whole planning should be performed including design, construction, operation and maintenance of the structures. Therefore, for the transportation system, the bridge is a key element [3] according to the following

with two points of the city, such as hospitals or fire stations.

areas for trade, distribution of goods and services.

points of the city with high traffic flow.

*Bridges: Structures and Materials, Ancient and Modern DOI: http://dx.doi.org/10.5772/intechopen.90718*

ture cannot maintain a continuous vehicular flow.

these trucks will have to plan an alternate route.

b. High cost for the entire road system

c. The bridge as part of the system

and the need of alternative route.

reasons:

the budget.

**95**

a. Capacity control


**Figure 1** shows a general view of Mexico City and the Vidalta cable-stayed bridge as transportation infrastructure, connecting via highways the whole series of multi-story buildings in the background.

According the previous infrastructure classification, all described structures do not work as isolated buildings. Instead, all elements must be connected looking for the harmony in a society, working effectively and should not affect any building performance.

As an example, there is a hospital that provides all types of medical treatment in an urban area. If the city's electrical stations stop working, the hospital will cease to be fully functional due to lack of electrical power, affecting medical equipment and lighting requirements. Now, if the same hospital has no enough roads for access, its capacity will be very limited, including medical staff and patients.

**Figure 1.** *View of Vidalta cable-stayed bridge, Mexico City [2].*
