Track usually consists of steel rails installed on sleepers/ties and ballast, on which the rolling stock, usually fitted with metal wheels, moves. However, other variations are also possible, such as slab track where the rails are fastened to a concrete foundation resting on a prepared subsurface. Railway transport is capable of high levels of passenger and cargo utilization and energy efficiency, but is often less flexible and more capital-intensive than highway transport is, when lower traffic levels are considered.
A railroad can consist of one or more tracks. There are public railroads, industrial railways and urban railroads - metro and tram.
The electrification system provides electrical energy to the trains, so they can operate without a prime mover on board. This allows lower operating costs, but requires large capital investments along the lines. Mainline and tram systems normally have overhead wires, which hang from poles along the line. Grade-separated rapid transit sometimes use a ground third rail.
A railway station serves as an area where passengers can board and alight from trains. A goods station is a yard which is exclusively used for loading and unloading cargo. Large passenger stations have at least one building providing conveniences for passengers, such as purchasing tickets and food. They are transport and interchange nodes of cities and have a transplant from trains on the metro, trams or buses. Smaller stations typically only consist of a platform.
The most important safety measures are railway signaling and building of bridges and tunnels on the crossings. Train whistles, bells or horns warn of the presence of a train, while track-side signals maintain the distances between trains. One of the effective methods of traffic safety of high-speed trains is construction of special separate tracks without crossings. This effectively eliminates the potential collisions with automobiles, other vehicles and pedestrians, vastly reduces the likelihood of collision with other trains and helps to comply with the schedules.
As in any infrastructure asset, railways must keep up with periodic inspection and maintenance in order to minimize effect of infrastructure failures that can disrupt freight revenue operations and passenger services. Because passengers are considered the most crucial cargo and usually operate at higher speeds, steeper grades, and higher capacity/frequency, their lines are especially important. Inspection practices include track geometry cars or walking inspection. Curve maintenance especially for transit services includes gauging, fastener tightening, and rail replacement. When tracks go alongside rivers the roadway is additionally strengthened in order to avoid leaching during floods. On turns of tracks they make additional calibration, regular tightening of fasteners and more frequent change of tracks.
While track servicing it is necessary to consider indicators of branches (types of trains, places of departure and destination, seasonal changes), capacity (length, soil, the number of tracks, types of signaling), capacity of trains (maximum speed, acceleration and braking) and features of dual use of tracks for passenger and cargo traffic (additional tracks, possibilities of endpoints, switching of arrows).