e. hosseini aria & r. ahooee islamic azad university, iran
TRANSCRIPT
E. Hosseini Aria & R. Ahooee Islamic Azad University, Iran
Introduction and Applications
Data integration architecture and strategy
Location referencing system and its data characteristics
Implementation
Department of Transportation (DOT)
Highway infrastructure
Highway infrastructure
Role of GIS in Transportation
Transportation is one of the most important and growing applications of GIS
GISGIS TransportationTransportation
GIS-TGIS-T
precisely count and locateprecisely count and locate
monitor their conditionsmonitor their conditions
track changes over time track changes over time
find unwarranted or “exception” signs and other find unwarranted or “exception” signs and other
equipmentequipment
help to determine whether additional signs neededhelp to determine whether additional signs needed
report generation from the databasereport generation from the database
monitor field maintenance and replacement programsmonitor field maintenance and replacement programs
Mashhad, Iran
An enterprise level of GIS-T that covering 300 Km of the city ways
PlacePlace
Transportation network data is complex since it is Transportation network data is complex since it is
often multi-modal, exists across many different often multi-modal, exists across many different
jurisdictions and has different logical views jurisdictions and has different logical views
depending on the particular userdepending on the particular user Transportation entities Transportation entities
physical descriptions logical relationships with other transportation entities.
Transportation entities
virtual world
real world
Logical Physical
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 Transportation Networks in a GIS: The Node-arc Model GIS: The Node-arc Model
The most common logical data The most common logical data model used to support the node-model used to support the node-arc representation is the arc representation is the relational model.relational model.
two coordinate methods two coordinate methods
(latitude/longitude)(latitude/longitude)
three-coordinate methods three-coordinate methods
(latitude/longitude/altitude) (latitude/longitude/altitude)
one-coordinate methods one-coordinate methods
Kilometer point method Kilometer post method Reference point method References post method Link node method
Reference point method
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 the central element of the multimodal GIS-T Data multimodal GIS-T Data Model considered as a Model considered as a transportation featuretransportation 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 transportation feature identificationidentification
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.