Railways in the context of Alaska

Infrastructure is the set of facilities and systems that serve a country, city, or other area, and encompasses the services and facilities necessary for its economy, households and firms to function. Infrastructure is composed of public and private physical structures such as roads, railways, bridges, airports, public transit systems, tunnels, water supply, sewers, electrical grids, and telecommunications (including Internet connectivity and broadband access). In general, infrastructure has been defined as "the physical components of interrelated systems providing commodities and services essential to enable, sustain, or enhance societal living conditions" and maintain the surrounding environment.

Especially in light of the massive societal transformations needed to mitigate and adapt to climate change, contemporary infrastructure conversations frequently focus on sustainable development and green infrastructure. Acknowledging this importance, the international community has created policy focused on sustainable infrastructure through the Sustainable Development Goals, especially Sustainable Development Goal 8 "Industry, Innovation and Infrastructure".

A trade route is a logistical network identified as a series of pathways and stoppages used for the commercial transport of cargo. The term can also be used to refer to trade over land or water. Allowing goods to reach distant markets, a single trade route contains long-distance arteries, which may further be connected to smaller networks of commercial and noncommercial transportation routes. Among notable trade routes was the Amber Road, which served as a dependable network for long-distance trade. Maritime trade along the Spice Route became prominent during the Middle Ages, when nations resorted to military means for control of this influential route. During the Middle Ages, organizations such as the Hanseatic League, aimed at protecting interests of the merchants and trade became increasingly prominent.

In modern times, commercial activity shifted from the major trade routes of the Old World to newer routes between modern nation-states. This activity was sometimes carried out without traditional protection of trade and under international free-trade agreements, which allowed commercial goods to cross borders with relaxed restrictions. Innovative transportation of modern times includes pipeline transport and the relatively well-known trade involving rail routes, automobiles, and cargo airlines.

Civil engineering is a professional engineering discipline that deals with the design, construction, and maintenance of the physical and naturally built environment, including public works such as roads, bridges, canals, dams, airports, sewage systems, pipelines, structural components of buildings, and railways.

Civil engineering is traditionally broken into a number of sub-disciplines. It is considered the second-oldest engineering discipline after military engineering, and it is defined to distinguish non-military engineering from military engineering. Civil engineering can take place in the public sector from municipal public works departments through to federal government agencies, and in the private sector from locally based firms to Fortune Global 500 companies.

Public capital is the aggregate body of government-owned assets that are used as a means for productivity. Such assets span a wide range including: large components such as highways, airports, roads, transit systems, and railways; local, municipal components such as public education, public hospitals, police and fire protection, prisons, and courts; and critical components including water and sewer systems, public electric and gas utilities, and telecommunications. Often, public capital is defined as government outlay, in terms of money, and as physical stock, in terms of infrastructure.

A transport network, or transportation network, is a network or graph in geographic space, describing an infrastructure that permits and constrains movement or flow.Examples include but are not limited to road networks, railways, air routes, pipelines, aqueducts, and power lines. The digital representation of these networks, and the methods for their analysis, is a core part of spatial analysis, geographic information systems, public utilities, and transport engineering. Network analysis is an application of the theories and algorithms of graph theory and is a form of proximity analysis.

Beijing, as the capital and one of the four municipalities of the People's Republic of China (PRC), is a transport hub, with a sophisticated network of roads, railways and two major airports. Six completed ring roads encircle the city with nine expressways heading in virtually all compass directions, supplemented by eleven China National Highways.

Transport in the capital is overseen by the Beijing Municipal Commission of Transport.

Parcel post is a postal service for mail that is too heavy for normal letter post. It is usually slower than letter post. The development of the parcel post is closely connected with the development of the railway network which enabled parcels to be carried in bulk, to a regular schedule, and at economical prices. Today, many parcels also travel by road and international shipments may travel by sea or airmail.

In meteorology, visibility is the measure of the distance at which an object or light can be clearly discerned. It depends on the transparency of the surrounding air and as such, it is unchanging no matter the ambient light level or time of day. It is reported within surface weather observations and METAR code either in meters or statute miles, depending upon the country. Visibility affects all forms of traffic: roads, railways, sailing and aviation.

The geometric range of vision is limited by the curvature of the Earth and depends on the eye level and the height of the object being viewed. In geodesy, the atmospheric refraction must be taken into account when calculating geodetic visibility.

The Chōsen Government Railway (朝鮮總督府鐵道, Chōsen sōtokufu tetsudō) (Korean: 조선총독부 철도; RR: Joseon Chongdokbu Cheoldo) was a state-owned railway company in Korea during Japanese rule. It was also colloquially known by the abbreviated name Sentetsu (鮮鐵). It was the operational division of the Railway Bureau of the Government-General of Chōsen (朝鮮總督府鐵道局, Chōsen sōtokufu tetsudōkyoku; Korean: 철도국; RR: Cheoldoguk), which managed and operated railways in Chōsen, as well as supervised privately owned railway companies.

Railway engineering is the discipline of engineering which concerns the design, construction, operation, and maintenance of railways and rail transportation systems. It includes a wide range of engineering disciplines, including (but not limited to) civil engineering, computer engineering, electrical engineering, mechanical engineering, industrial engineering and production engineering.