Editing Rail transport (section)

===Maintenance===
As in any [[infrastructure]] asset, railways must keep up with periodic inspection and maintenance to minimise the 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 car]]s or walking inspection. Curve maintenance especially for transit services includes gauging, fastener tightening, and rail replacement.

Rail corrugation is a common issue with transit systems due to the high number of light-axle, wheel passages which result in grinding of the wheel/rail interface. Since maintenance may overlap with operations, maintenance windows (nighttime hours, [[off-peak hours]], altering train schedules or routes) must be closely followed. In addition, passenger safety during maintenance work (inter-track fencing, proper storage of materials, track work notices, hazards of equipment near states) must be regarded at all times. At times, maintenance access problems can emerge due to tunnels, elevated structures, and congested cityscapes. Here, specialised equipment or smaller versions of conventional maintenance gear are used.<ref name="AREMA. 2003. Practical Guide to Railway Engineering"/>

Unlike [[highways]] or [[road network]]s where capacity is disaggregated into unlinked trips over individual route segments, railway capacity is fundamentally considered a network system. As a result, many components are causes and effects of system disruptions. Maintenance must acknowledge the vast array of a route's performance (type of train service, origination/destination, seasonal impacts), a line's capacity (length, terrain, number of tracks, types of train control), trains throughput (max speeds, acceleration/ deceleration rates), and service features with shared passenger-freight tracks (sidings, terminal capacities, switching routes, and design type).<ref name="AREMA. 2003. Practical Guide to Railway Engineering"/>