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.