Graphicage and preparing

The graphicage and the preparing are techniques employed in the field of the Public transport travellers to organize and envisage rationally the daily tasks of the vehicles and drivers.

The graphicage

In the field of the Public transport travellers, the graphicage is the action to design the tables of walk of the vehicles. A table of walk is the whole of displacements of the vehicles on a way given for one day standard (for example one Monday in school period).

The graphicage consists in successively connecting in time the races of line (commercial way between two successive termini) between them by means of races hauts-le-pied (way carried out except business service). Each sequence of races defines a service conveys which will be carried out by the same vehicle. The graphicage is complete when the whole of the races were planned in a service conveys.

The graphicage is held in three principal stages:

design of the time offer
the diagrammatic representation
the chaining of the races

Design of the time offer

The graphicage is always preceded by a specific stage of design of the time offer consisting in defining the frequency and the route of the races for each line and each standard day. The determination of this offer must answer a a whole series of constraints, among which:

the answer to the needs for displacement of population (capacity of answer to the load of removal, service road of the schools, respect of the intermodal correspondences, etc)
the financial expenses lends to being committed by the community and/or the operating company (many vehicles and of drivers, etc).

Diagrammatic representation

Once the established time offer and in order to facilitate the task of the owner, one represents the objects graphically to be planned (mainly races). There exist two means of representing the tables of walk schematically.

Graph flat

The graph flat is a representation in the form of Bar chart of the races of the table of walk. Time is given on the horizontal axis and the objects (services cars) of the table of walk are laid out vertically.

Graph of line

The graph of line is composed in X-coordinate of time (hours of the day) and in ordinate of the distance (succession of the stops served by the line). Each race is represented by a feature connecting the stagnation points laid out in the space time of the diagram. In a graph with variable slope (the most current representation), the batter level indicates the speed of the races: the closer the feature is to the vertical, the more speed is high and the closer the feature is to horizontal, plus speed is weak.

In a graph with constant slope, the slope of the races being identical, speed is located by the variable height of the graph: the lower the graph is, the more speed is raised and the higher the graph is, plus speed is weak.

Chaining of the races

The graphicage itself consists in connecting in time the races between them and to supplement this chaining by a race Haut-le-pied of exit of the deposit and a race Haut-le-pied of return to the deposit. When two races are connected one to the other with a terminus, time separating the arrival from the first race at the beginning of the second is called time of beat.

The time of beat includes the time necessary with the vehicle to move stop of arrival to the starting stop (race of reversal) and the time of parking to the terminus. This time of parking is made profitable by the driver to update possibly the panels of information traveller, to accommodate the passengers on board and especially to make up for possible lost time undergone on the preceding races.

The preparing

Once the graphicage carried out, the following stage consists in cutting out the services cars in sections of preparing which will form the conducting services (task of work carried out by a driver within the one day's work old framework) by taking account of the regulations in force and the company agreements. The preparing is thus the fact of defining conducting services entirely covering the services cars.

The section of preparing is a basic unit of the conducting service delimited by deposits and/or points of changing, i.e. the places where the driver can take possession of the vehicle out of the deposit, generally at a stagnation point on the network. It is thus a continuous section where the driver cannot be replaced in its task of control.

The preparing is always represented schematically in the form of Bar chart, each line containing a conducting service.

Computer tools

The graphicage and the preparing were conceived a long time with the pencil on sheets of paper graduated. Today the majority of the companies of public transport employ a specific Logiciel. The software of exploitation allow inter alia accelerating the work of design considerably, to reduce the risks of error of design (lapse of memory, inconsistencies…) and to assist the user in his task thanks to algorithms of optimization.

Many editors share the worldwide market. Let us quote for example the software MICROBUS of German company IVU Traffic Technologies AG or Hastus of the Canadian company Giro, two of the editors of Logiciel of exploitation in Public transport most known in Europe.

Simultaneous Graphicage and preparing

If the graphicage and the preparing were treated a long time like two successive tasks, the modern computer tools make it possible from now on to treat them simultaneously, as it is the case with MICROBUS.

The fact of carrying out and of optimizing the services cars and drivers jointly makes it possible to lead directly to solutions of conducting services powerful, without to and from between the phases of graphicage and preparing, in particular in the field of regional transport or interurban. Indeed, contrary to the urban transport where the lengths of the lines are relatively short and where the high frequencies of the races allow many possibilities of changings, interurban transport offers few possibilities for the driver of leaving its vehicle and of being replaced. Consequently, the changings are rare and the service car will often coincide with the conducting service. However, since the constraints weighing on the formation of the conducting service (regulation of work, etc) are stronger than on the service conveys, the preliminary stage of graphicage is often a waste of time.

Thanks to such software, it is then possible, directly starting from the races, to define solutions of conducting services optimized for regional transport while jumping the stage of the graphicage.

See too

External bonds

Presentation in French of the software of graphicage and preparing MICROBUS
Official site of the editor of MICROBUS
Official site of the software Hastus
Official site of the software HOURS

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