Proceedings of 7th Transport Research Arena TRA 2018, April 16-19, 2018, Vienna, Austria Development of VISSIM generator based on OpenStreetMap Dzenan Dzafic, M.Sc. a*, Leon Oss, B.Sc. a Christian Dernehl, M.Sc. a, Dipl.-Ing. Miriam Geulen b, Univ.-Prof. Dirk Vallée b, Univ.-Prof. Stefan Kowalewski a a Embedded Software (Lehrstuhl für Informatik 11), RWTH Aachen University, Ahornstrasse 55, 52074 Aachen, Germany bInstitute of Urban and Transportation Planning, RWTH Aachen University, Mies-van-der-Rohe-Straße 1, 52074 Aachen, Germany Abstract VISSIM is a popular tool for traffic simulation. Before the simulation can be started, a model of the road network must be created which is a mostly manual and therefore tedious and time-consuming process. We present a VISSIM model generator which reduces the time spend for this task considerably. The generator creates a VISSIM model from an OpenStreetMap (OSM) file, which can be used by engineers as a skeletal structure. It creates all links, connectors, desired speed decisions, reduced speed areas and vehicle routes in a chosen area. Then the engineers can directly start with the parameterization. The architecture of the generator is client server based. This means the user chooses in his browser an area on the OSM map. Then this information goes to the generator. Consecutively, the generator loads the map data from the OSM server and processes them to a VISSIM model, which the user can then download. To add more valuable information, the generator will be extended to include hold lines recognized on aerial images. The evaluation shows, that using the generator saves some hours to the users. Keywords: VISSIM, Generator, Modell, OpenStreetMap, Automatization 1. Introduction Microscopic traffic flow simulation is an established technique for mapping and simulating the traffic flow at junctions, on routes and in networks. The VISSIM program of PTV AG is a widely used tool for traffic flow simulation. Before starting a simulation study, the planning area in VISSIM must first be modelled. This requires information on the routes, the number of lanes, the traffic regulations and the position of stop lines and signal heads. The construction of the network in VISSIM and the adjustment to the real situation are time-consuming. The question therefore arises as to whether this time expenditure can be reduced by automatically generated VISSIM networks. In this paper the VISSIM network is generated using publicly accessible data. The open source project OpenStreetMap (OSM) provides with its information freely accessible map material and geodata. The paper is organized as follows. First, two software products are presented, which can also be used to generate VISSIM networks. Chapter three describes the basics that are relevant to the development of the generator. Building on the foundations, the generator is presented with its architecture and its features (chapter 4) and then evaluated in chapter five. In the end, upcoming work steps will be presented and an outlook will be given (chapter 6). 2. Related Work In this section, we discus two programs which can generate VISSIM models with OSM Data. The first one is VISUM, which is like VISSIM a product of PTV (2016). VISUM can import OSM Data to an own network, and export a network to VISSIM. Primarily it is for macroscopic transport modelling and not build to generate models in VISSIM. Macroscopic models do not need exact geometries in contrast to VISSIM models. This affects the quality of the approach to use VISUM for Microscopic simulation. Apparent in the fact that the generator VISUM only creates links and connectors. The links on a crossroad in the VISUM network all meet in one point. This makes it difficult to adjust it. The generator, described in this work, shortens the links at crossroads to avoid this. The generator and VISUM both add Desired Speed Decisions to the network. VISUM also adds conflict areas, which are used to model priority in the traffic. In VISSIM there is also a node object, which is different to the node object in OSM. This object is used to evaluate the traffic later. VISUM adds such nodes on each crossroad. The VISSIM-Generator does not do this, because the engineers wish to mark own nodes in the network. The second software to generate a VISSIM model with OSM data is VS-SimGen by Verkehrs-Systeme AG (2017). VS-SimGen uses NAVTEQ data, which is more detailed than OSM. In contrast to VISUM, VS-SimGen is made to generate VISSIM models. The features of VS-SimGen are the following: • Generation of links and connectors • Desired Speed Decisions • Conflict areas • Stop signs In contrast to the VS-SimGen and other generators the proposed generator adds vehicle routes. They are used in almost every model and are therefore an important feature. The generator only creates the routes, without usage distribution, so the user must add them per hand. 3. Basic This chapter introduce some basics to help with the understanding the content of this paper. It starts with the definition of the eXtensible Markup Language (XML), which is the language that describe OpenStreetMap (OSM) and the PTV VISSIM. Since VISSIM is the simulation software used for the work introduced in this paper, it will be the next topic to be introduced. It is also crucial to the comprehension to know that the OSM builds the map foundation. 3.1. eXtensible Markup Language (XML) The W3C (World Wide Web Consortium) developed the XML Language with the goal to overcome some limitations in HTML. The name XML means eXtensible Markup Language and defines a package of rules to encode documents in a format that can be read from both humans and machines - Marchal (2002). XML works with the concept of key-value pairs. For example, in the OSM document (Fig. 1), one key is highway and one of the associated values is residential. An XML documents is composed out of elements. An element can have Fig. 1 XML Code some attributes and some elements in a lower hierarchy (Fig. 1). The element within the lower hierarchy is called child. The higher element is called parent. 3.2. VISSIM VISSIM is a program of PTV AG for microscopic traffic flow simulation. This tool is state-of-the-art and is, according to the company, “the leading microscopic simulation program for modeling multimodal transport operations” PTV (2016). VISSIM includes a traffic flow model and a signal control. The traffic flow model simulates the movement of different road users through a network. The model is based on a car following model and on a lane-changing model. VISSIM uses the psychophysical perception model developed by Wiedemann for modeling the car following. The network consists of the following components: A. links, number of lanes, connectors, public transport stops, stop line and positions from signal heads and detectors B. Vehicle inputs, routes, headway and time gaps from priority rules, information from public transport lines e.g. departure time. The first ones describes static data, which does not change during the simulation. The second components are dynamic data, which can change. PTV (2016) A VISSIM file uses XML to save data. Every network has a root called network with children for every object in the model. Some of the children are in every VISSIM file. For example, desSpeedDistributions stores the standard speed distributions for VISSIM. Some of the children of network are not in every VISSIM file. An example for this is vehicleRoutingDecisionsStatic. This element is added, when the user saves vehicle routes. Later the generator uses this modular construction of a VISSIM file, to add features independently. 3.3. OpenStreetMap (OSM)) OSM is the best open source project found to use as map source for the proposed generator. According to Ramm F and Topf J (2010), no other open source project exists with a comparable world map data density and reliability like OSM. As mentioned above, the data format of OSM is XML. Additionally, other data input can be used by adding new tags to a model. The main structure of OSM files consists of three components: node, way and relation. The node gives information about position (Latitude - Longitude), traffic signals, stop signals, etc. Secondly, ways connect some of the nodes and gives information about the following topics: • highway – Provides information about the sort of roads • lines – Provides information about the number of roads tracks • maxspeed – Provides information about the maximal licensed speed • oneway – Provides information weather a street has an opposite lane • junction – Provides information weather we have roundabout traffic Lastly, a relation connects the ways. The VISSIM Generator needs only the information of nodes and ways to build VISSIM files that are also based on XML. 4. Generator 4.1. Architecture Fig. 2Architecture of VISSIM Generator The architecture of VISSIM generator (Fig. 2) is based on client-server. This means that a user chooses one quadrant from the map on the desktop (clients). The coordinates of this quadrant will then be sent to the VISSIM generator server. Since the VISSIM generator has no data about the map, this server needs to send a request with the coordinates to a data source. In this case the data source is the OSM Server. After the VISSIM generator receives a XML file with all information about the map from the OSM server, the VISSIM generator begins to parse the road information from OSM to VISSIM. At first the generator matches the tags of the XML file from the OSM format to the VISSIM format. After this matching, the VISSIM generator starts converting the OSM information to the VISSIM format. Afterwards the generator generates further features for the VISSIM model. More information about the functionality of the parser can be found on the chapter 4.2 of this paper.
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