gis system usage in the road network planing in cities
Tomasz Szczuraszek
Jan Kempa
Grzegorz Bebyn
Jacek Chmielewski
University of Technology and Agriculture
Bydgoszcz
Poland
jacekch@mail.atn.budgoszcz.pl
1. The Basic System’s Elements
The Transportation Planning Informatic System (TPIS) is a tool that help to make decisions about planning of traffic infrastructure development and public transport functioning in towns. At the same time it is a database containing information relating to population and spatial management in towns. What is more it contains forecasted travel demands of inhabitants, traffic and bicycles volumes and public passenger transport’s flows on a town’s road network. The project designed for the town of Bydgoszcz (the town of about 400 thousand inhabitants and area of 175 km2) is called TPIS-Bydgoszcz.
The following computer applications are used to manage the TPIS-Bydgoszcz project:
The software includes, except environment software, also TPIS’s application for creating graphic-descriptive database, for database browsing and for data analysing. Those application were developed by the authors in MDL language (MicroStation Development Language).
The TPIS-Bydgoszcz project was built in the multitasks 32-bits WINDOWS NT environment, what considerably raises quality and effectiveness of the whole project working.
The system’s project consists of three dependent on each other basic blocks of:
The block of data collecting and processing serves data to the block of database, and this one to the block of data analyses.
The most important part of TPIS-Bydgoszcz project is the block of database.
The block contains data on:
Each of mentioned elements of the database’s block is created in a graphic and descriptive form (as tables of the text database). For database creating additional applications were developed. They help to put in graphic and text data to the system.
The basic goal of the data analyses block is a graphical presentation of flows on particular transport networks and determination of travel demands in particular zones. In the future this block will be enlarged with new elements resulting from requirement of detail data analyses. The block is created also in a graphic form (maps and thematic graphs) and in a descriptive form (tables) by the adequate applications. Data analysis is being made automatically in the system.
The block of collecting and processing data refers to all data contained in the TPIS-Bydgoszcz project. This block is supported by various software units and by applications made by PTV company: VISEM, VISUM IT and PT [8, 9, 10]. Therefore it includes both data from direct inventarization (data about market, schools, inhabitants) and results of analyse made by PTV applications (data about inhabitants’ travel demands, results of traffic assignment into the road network, etc.). It is provided that particular data will be updated every five years, and forecasts will be continuously updated allowing changes in inhabitants’ behaviour. However it is assumed that data from direct inventarizations for the given year of analysis can not be modified.
2. Workstations arrangement in the computer network
The scheme of connections among particular computer workstations and applications used in the TPIS-Bydgoszcz project are shown on fig. 1.
The TPIS-Bydgoszcz project has got the text database called TPIS, connected to MicroStation with the RIS scheme called TPIS. The goal of RIS application is to send text data in the computer network between the database server and workstations. This process is compatible to the given RIS scheme. The idea of text data transmission between the database server and particular workstations is shown on the fig. 2.
Fig. 1. The scheme of links between several workstation and applications used in TPIS-Bydgoszcz project.
Fig. 2. The idea scheme of text data transmission between the server and a workstation in computer network
3. Basic elements of the database block
The database of TPIS-Bydgoszcz project is built according to the structure given in MGE-PC application developed by Intergraph Corporation.
The database project is a set of information stored as graphics data (maps) and text data (tables). Features are the elements linking a graphic and a text part of the database. Some auxiliary tools are used to help with creating, completing and browsing database. The tools are: MGE-PC application useful for linking graphic elements with the text database and for serving the project; applications developed by the authors of the TPIS-Bydgoszcz project, helping to work with the project; VISTAMP application that allows to browse the graphic-descriptive database. Fundamental elements of the discoursed project’s database are shown on fig. 3.
Fig. 3 Fundamental elements of the database block in the TPIS-Bydgoszcz project.
Detailed description of the database construction is illustrated on fig. 4. Maps in the database are grouped thematically in corresponding categories: Public Transport Network, Bicycle Transport Network, Traffic Network, Topography and Town-Planning. Maps of the MGE-PC application are an exception because they are only work maps of the database.
We can particularise three sorts of tables in the descriptive part of the database: system tables, features tables and auxiliary tables. The basic description of database elements is included in features tables that are also grouped in categories, as maps they are related to.
System and auxiliary tables are created independently to the graphic part of the database and they are not linked to graphic elements, because they are a work element of the database.
Features are elements of the graphic database. They are grouped in the same categories as maps.
There are two basic elements of the graphic database:
Some examples of maps used in the database are shown on fig. 5 and 6.
Fig. 4 The idea schema of the database block in the TPIS-Bydgoszcz project.
Fig. 5. The map of town partition into traffic zones.
.
Graphic characteristic of traffic area’s accessibility – fragment of a map |
Fragment of public transport network |
Fragment of traffic network |
Fragment of bicycle trips network. |
Fig. 6. Fragments of traffic network’s maps of Bydgoszcz town.
4. Data analyses block
The basic goal of data analyses block is to make analyses of data contained in database of the TPIS-Bydgoszcz project and next to present their results in a graphic and descriptive form. The analyses are made basing on a graphic and text database.
Analyses based on graphic are made with visual estimation of particular network elements of an examined area, furthered with descriptive data referring to particular features on maps. The analyses refer to traffic conditions on a traffic network in relation to twenty-four hours or to a pick hour, indicators of passenger flows on the public transport network, etc.
Analyses based on the text database are made with specially developed functions in the TPIS MANAGER application. These functions allow to analyse changes in capacity of traffic flows, tendency estimation of changes in population in particular behaviourally homogeneous groups for the particular zones, description of changes in travel demands of inhabitants, etc. The list of those functions with their description is shown in the table 1.
Table 1.
The list functions in TPIS MANAGER application assigned to data analyses.
Subject of analysis |
Application name |
Value of daily traffic volume on road network |
Network graphs |
Value of pick hour traffic volume on road network |
Network graphs |
Value of road network charge indicator |
Network graphs |
Value of daily passengers flow on public transport sections on different transport modes |
Network graphs |
Zone number determination for a given street |
Zone number for a street |
Determination of daily transportation flows between two zones separately for different transportation modes for particular years of forecast |
Travel demands in zones |
Analysis of traffic network charge for particular years of forecast |
Traffic network description |
Analysis of changes in spatial management and inhabitants number in zones for particular years of forecast |
Zone description |
In the future it is planned to extend the data analyses block with elements resulting from different requirements of thorough data analyses.
Some chosen results of data analyses acquired in the system are shown on fig. 7, 8, 9 and 10.
.Fig. 7 Fragment of the map of traffic volume in a pick hour.
Fig. 8 Matrix of transit traffic for the city of Bydgoszcz
Fig. 10 Distribution of the travel length for working people with a car available for different transport mode.
5. Advantages and disadvantages of the project.
The presented TPIS-Bydgoszcz project, because of its construction, is an effective tool for transport network’s planning. Doubtless advantages are among the others:
Literature
PTV System Karlsruhe: VISUM PT, Interactive Planing Tool for Public Transport,