• What is the purpose? – This ontology is developed to represent concepts needed for the conceptual design of roads, mainly focused on design of rural roads in germany. Its goal is to share the knowledge with people (Musen 1992; Gruber 1993).
• What is the scope? – This ontology includes the „Guidelines for the design of rural roads“ (RAL) for new roads as well as reconstruction of old ones (FGSV, 2012)
• Who are the intended end-users? – The intended end-users are the designers and engineers involved in the design/redesign process of standardized roads.
• What is the intended use? – The ontology is intended to be used as knowledge representation to support the design process , specifically targeted at understanding the relations of the design stepsThe following taxonomy is the result of the initial research. The anthology shows the common design process of rural roads following RAL guidelines.

  • basic design features • connection function
  • cross section
  • design class

  The decision to include those four categories is argued as follows:
  The basic design features include all essential design parameters of the road. Those aim to influence the behavior of the driver by creating visibility and distinction of different roads. The basic design features are the planning speed which varies form 110km/h to 70km/h, the mode of operation- motor way or general traffic, the cross section, rules for cyclers, radius ranges and cost radius, percentage of secured overtaking sections per lane and longitudial inclination threshold. This principles ought to improve traffic safety. Standard cross sections of roads are established in the RAL. This is responsible for the dimension of the road itself. It contains information about the width of the road as well as number of lanes, the lane width, shoulder size and if the road has a overtaking strip.
  The connection function which determines the design class refers to the importance of the road. Therefore „I“ refers to the highest priority and „IV“ to the lowest. The classification design is out of scope, because its part of „RIN“ guidelines. The connection function determines the design class directly. Each design class corresponds to a set of design features and a cross section.
  As Krötzsch recommends the concepts are close to logical objects of the RAL guidelines.

  Interfaces

  The design classes are directly influenced by their connection function in the traffic system (RIN) (FGSV, 2008a). For example LS1 is the highest priority rural road and therefore is assigned to the EKL1 design class which affects its structure and conceptual design essentially.
  The layout of a street is influenced by geological factors and the location of forests or nature reserves according to stage 3 „Bundesverkehrswegeplan 2030“, which assesses the impact on nature.

  Ontology

The ontology

It starts with the the connection function because there the RAL starts its classification there. The process from the importance to its final design has been included in the ontology. The rural road has exactly one specific connection function and a Data property „has location“. Its modeled in the onthology by at least/at most restriction of one, there are no roads with more than one connection function. The connection function determines the design class, therefore it is modeled in the same manner by using restriction. The same applies for DesignClass and BasicDesignFeatures. A DesignClass has at least 10 BasicDesignFeatures, which is implemented by a at least ten restriction. BasicDesignFeatures define exactly one CrossSection.

The object properties are defining those connection between design steps. For example the hasDesignFeatures object property, which has DesignClass as a Domain and BasicDesignFeatures as Range shows that the DesignClass defines the DesignFeatures in the design process. IsBasicDesignFeatureOf is the inverse of hasBasicDesignFeature. In the same manner other connection where implemented.

The instances represent the specific design process for each rural road. The B 169 is located in Brandenburg and therefore has a data property assertion hasLocation. Moreover the first step would be to define its connection function. According to “Berichthefte der Bundesanstalt für Straßenwesen“ it is classified as „I“ – high priority. Now the object property assertion hasConnectionFuntion min/max 1 connection function meant to implement that. This applies for

Image 1: OntoGraf view of road design onthology

the rest of the process until the last individual is reached – BasicDesignFeatures_EKL1 in this case. This contains all information about the final design of the road ranging from having one specific cross section as a object property to doubles, booleans etc. for other necessary to plan a road.