Presentation on theme: "E. Hosseini Aria & R. Ahooee Islamic Azad University, Iran."— Presentation transcript:
E. Hosseini Aria & R. Ahooee Islamic Azad University, Iran
Introduction and Applications Introduction and Applications Data integration architecture and strategy Data integration architecture and strategy Location referencing system and its data characteristics Location referencing system and its data characteristics Implementation Implementation
Role of GIS in Transportation Transportation is one of the most important and growing applications of GIS GIS Transportation GIS-T
precisely count and locate monitor their conditions track changes over time find unwarranted or “exception” signs and other equipment help to determine whether additional signs needed report generation from the database monitor field maintenance and replacement programs
An enterprise level of GIS-T that covering 300 Km of the city ways Place
Transportation network data is complex since it is often multi-modal, exists across many different jurisdictions and has different logical views depending on the particular user Transportation entities physical descriptions logical relationships with other transportation entities. Transportation entities virtual world real world
LogicalPhysical Real Legal definitions - Route - State trunk network - County trunk network - Street network - Political boundary Actual facilities - Highways - Roads - Interchanges - Intersections Virtual Data structures - Networks - Chains - Links - Nodes - Lattices Data values - Lines - Points - Polylines - Polygons - Attributes
Transportation Networks in a GIS: The Node-arc Model The most common logical data model used to support the node-arc representation is the relational model.
Accuracy road asset/event locations accuracy = ±3 to 5 meters (at 90% confidence) the maximum reference section distance should be no longer than 8 km. Resolution Is closely related to the scale. 1:2000 Precisian
the central element of the multimodal GIS-T Data Model considered as a transportation feature After determining reference points in the field, crews were performing length measurement for each event/asset related to a reference point and writing down attributes of that event/asset in inventory forms.
transportation feature identification Exp: the number 18203822 determines the path between the junctions 1820 and 3822. Therefore in relational database, a field has been added for all linear transportation features that identify a path between two junctions.
Transportation feature database design roadways (corridors) cross section elements Sidewalks urban furniture lining Grates of infrastructures special problem (line & point data) public transit data special land use on network lighting junction These data include information about transportation features and non-transportation features that affect on traffic.