Occupancy rate
The occupancy rate is a characteristic of the railway . It describes the proportion of time that track elements are occupied by trains or shunting units. It is usually given without a unit (between 0 and 1).
The guideline for track capacity of the Deutsche Bahn defines the degree of occupancy as the "[z] ual [n] portion of which a track section or network element is occupied by train paths or train positions within the investigation period or evaluation period (in the sense of operational stress), ie not for other trains It differentiates between the individual occupancy rate , which relates to a section of the route ( block section , route , part of the route) and the linked occupancy rate , which consists of a network element that consists of several route sections that are to be cleared and which are used successively during a train journey , for example on a route. The linked occupancy rate results from the sum of all minimum headway times for the evaluation room (e.g. routes, overtaking sections) in relation to the evaluation room.
If the occupancy rate is only determined for individual block sections , it should be noted that the free time gaps are not always available for train journeys. For example, if a fast train is followed by a slow train, the time gap between the two trains increases without a train being able to travel there. The interdependence of train journeys is called chaining . The occupancy rate, taking this dependency into account, is called the chained occupancy rate .
Demarcation
The interlinked occupancy rate is usually specified between two stations in which the sequence of trains can be swapped (overtaking) or in which train crossings can take place (for single-track routes). Another delimitation that is practiced is based on current operating programs. Section boundaries can be where the mix or the number of trains changes significantly, i.e. where trains already end, begin, cross or overtake today.
Quality standards
Using the linked level of occupancy, it is possible to quickly estimate whether the railway systems are overloaded. If the total operating time is considered, it should not be significantly more than 0.5. In the peak hour, 0.8 should not be exceeded.
Free capacity
The reciprocal of the degree of occupancy is the degree of buffer time , which describes the proportion of unused capacity (buffer). A high degree of buffer time suggests that more trains can be inserted.
This statement is not generally applicable. Further trains can only be inserted if the time gaps are such that no other train is hindered and the new train also finds suitable time gaps in the neighboring sections. A statement about free capacity can therefore only be made after further timetable studies .
Individual evidence
- ↑ a b DB Netz AG: Guideline for Track Capacity . Guideline 405, Module 0102, valid from January 1, 2008, page 4.
- ^ DB Netz AG: Guideline for Track Capacity . Guideline 405, module 0104, valid from January 1, 2008, page 28.
- ^ Jörn Pachl, System Technology of Rail Traffic, Teubner-Verlag Stuttgart 1999.