1. NCHRP 20-64
XML Schema for Transportation Data Exchange: Project Overview and Status
Last Updated:
April 30, 2005

2. Presentation Overview
XML 101
TransXML Project History, Scope and Objectives
Phase I Results
Phase II Status
GML Experiment
Future Stewardship

3. XML 101 XML stands for eXtensible Markup Language XML is:
widely adopted way of info exchange across web applications
human-readable and self-documenting
application independent
An XML schema is a data structure
XML schema value depends on getting agreement across software vendors and agencies that produce and consume info – this is the hard part

4. XML Examples in Transportation
LandXML – roadway design info
aecXML – construction pay items
AASHTO Trns*port construction management – data exchange between modules
AASHTO Virtis/Opis – XML import and export routine
AASHTO TSIMS (proposed)
JusticeXML – driver records, arrest warrants
Location Referencing Specification (SAE J2266)
ATIS – XML vocabulary for Traveler Information Exchange
GML – geographic markup language (object model & rules for developing XML schema)
TranXML/Logistics XML
TMML – Traffic Model Markup Language – data exchange across traffic modeling software packages
FMCSA – motor carrier profile, safety audit, driver/vehicle/carrier clearance

5. TransXML Project History
Initiated by AASHTO’s Technical Applications and Architecture (TA&A) Task Force
Driving Forces:
Growing support for data exchange standards within DOT community – given ITS experience, increase in web apps
LandXML success – sharing of road design info
AASHTOWare program interest in migrating to XML as data exchange method in all products
Desire to coordinate/fill gaps in multiple fragmented XML efforts: construction, design, safety, GIS, ITS

6. TransXML Project History (continued)
NCHRP Project created with a $500,000 budget
Awarded December 2003 and contracted March 2004
2 year effort – completion in March, 2006

7. NCHRP Research Team
Cambridge Systematics – Business Lead & Safety Schema
Bentley Systems Inc. – Technical Lead & Survey/Design Schema
Michael Baker Jr., Inc. – Bridge Structures Schema
Info Tech, Inc. – Construction Schema
Chuck Campbell, XML Consultant

8. Panel Members
Loren Risch, P.E., Kansas DOT, State Bridge Engineer, Chair
Steve Brown, P.E., Nebraska DOR, AASHTO Monitor
Dr. Roemer Alfelor, Federal Highway Administration
Todd Bergland, Minnesota DOT
Lyman Hale III, P.E., New York State DOT
Maurice Harmon, HNTB Corporation
Liang Hsia, P.E., Florida DOT
David Lively, P.E., California DOT
Thomas Rioux, P.E., University of Texas – Austin
Sandra Salazar, Johns Hopkins University
Gregory Witt, Kentucky Transportation Cabinet
Mary Beth Leaf, AASHTO Liaison
FHWA Liason - James Pol, ITS Transportation Specialist
AASHTO Liason – Thomas Palmarlee
NCHRP Staff – Chistopher Hedges, Senior Program Officer

9. TransXML Project Objectives
Develop broadly accepted public domain XML schemas for exchange of transportation data
Recommend institutional framework for future schema development and dissemination
Initial focus on four business areas:
Survey/roadway design
Transportation construction/materials
Highway bridge structures
Transportation safety

10. Potential Benefits of TransXML
Status Quo
Future Vision
Proliferation of inconsistent, overlapping data standards
Time consuming to transfer data across applications
Duplicative data entry
Limited access to information across functional areas in an agency
Technology change limits access to archived legacy data
Coordinated, widely used core data standards
Open, non-proprietary data formats adopted
Automation of data transfer
Sharing of information across planning, design, construction and operations
Data archived in accessible, self-documenting format
LandXML:
XML standard for civil engineering and land survey data
Supported by 30+ applications including all major civil engineering packages, FHWA ISDHM
Demonstrated benefits
Faster & Easier data exchange across applications
Use of LandXML for control of GPS-guided excavation equipment
AASHTOWare:
Desire for Open Data Formats to Allow for Interoperability:
Construction Management
Bridge Rating & Design
Bridge Management
TSIMS
Research Community:
Recognition of XML’s emergence as major data exchange format
Multiple standards emerging
Investigate creation of coordinated mechanism for schema development

11. Project Timeline Identify Long-Term Transportation Business Areas
Phase I: March 2004 – September 2004
Identify Long-Term Transportation Business Areas
Review Existing Schema
Assess Gaps and Identify Best Initial Opportunities
Investigate Stewardship Options
Develop Plan for Phase II
Products: Interim Report & Collaboration Web Site

12. Project Timeline Develop Schemas with Stakeholder Input
Phase II: November 2004 – March 2006
Develop Schemas with Stakeholder Input
Scope Refinement
UML Modeling
XML Encoding
Develop Sample Applications and Validators
Implementation & Stewardship Recommendations
Products: Final Report, Schemas and Sample Applications

13. Project Approach Business Process – Driven Stakeholder Consensus Focus
Design schema based on the functional context for data exchange, not based on data modeling alone
Stakeholder Consensus
Widespread adoption is critical to success
Involve broad range of stakeholders
Focus
Limit scope to highest priority standardization needs
Maximize initial benefits to transportation agencies
Establish framework for continued efforts

14. Phase I Results

15. TransXML Current and Possible Future Scope
Survey/
Design
Construction/
Materials
Bridge
Safety
Asset
Management
Maintenance
Management
Project
Development
Program
Development
Operations/ ITS
Modeling/
Simulation
Geospatial
Data
Freight/
Logistics

16. Assessment of Gaps & Opportunities
TransXML
Survey/
Design
Construction/
Materials
Bridge
Safety
What schemas and standards exist?
What are the major data exchange needs?
What hasn’t been addressed?
What are the best opportunities for TransXML?

17. TransXML Gaps and Opportunities Survey/Design – Current Schema
LandXML
Alignments
Coordinate Geometry Points
Grade Model
Surfaces – point, linear, triangle
Parcels
Roadways (IHSDM)
Survey Equipment and data
Geotechnical XML
Soil testing results
aecXML Infrastructure
Pay Items
Pay item prices for design estimates
Geographic Markup Language
Geometries (points, curves, surfaces, solids, composite)
Topologies
Location & Coordinate Reference Systems
Measurement Units
Metadata
Presentation Styles

18. TransXML Gaps and Opportunities Construction/Materials – Current Schema
aecXML Common Object Schema
Projects
Documents
Materials
Proposals
aecXML Infrastructure
Project Description
Project Location
Special Provisions
Funding Sources
Pay Items
Pay item units of measure
Pay item prices
AASHTOWare Trns*port
Construction Contract
Daily Work Report
Geotechnical XML
Soil testing results

19. TransXML Gaps and Opportunities Bridge Structures – Current Schema
NCHRP – Bridge Analysis & Rating Inputs – Steel Girders, Pretensioned Prestressed Concrete Girders
Structural analysis results
Section properties
Specification information
NCHRP 20-7 SteelBridge XML – content for steel bridge fabrication and construction
Virtis/Opis data structure – XML output
LEAP Software – design & rating (proprietary)
WSDOT – no schema, but data storage format (open source)

20. TransXML Gaps and Opportunities Safety – Current Schema
Justice XML Data Model
Driver license/history
Citations
Driving Incidents
Motor Vehicle Licensing
Crash Records Markup Language (CRML)
Crash data
ITS Incident Management Message Sets (IEEE )
Location Referencing
GOS Road Theme (includes ISO linear referencing standard)
XGDF Roadway Navigation
FMCSA
Motor Carrier Profile
Inspection Selection System
Safety Audit
Driver/Vehicle/Carrier Border Clearance
TraCS

21. TransXML Schema Development – Best Opportunities
Potential to save time & money by:
Allowing re-use of information
Allowing agencies to analyze the same data set with multiple applications
Criteria:
Large # users for same information
Data relatively static in nature
Complexity & criticality
Ease of consensus on standard
Incentives for adoption

22. Candidate XML Schema for Phase II
Survey/Design
Improvements to LandXML
Contract pay items Design  Construction
Area feature support – GIS  CAD
Construction
Daily construction progress –Field  Central Office  Lab
Construction status reporting – web, stakeholder systems
Bridge
Structure description for design and rating
Safety
Crash Records
Highway Inventory Data for Safety Analysis

23. TransXML Gaps and Opportunities Survey/Design – Best Opportunities
Exchanging Roadway Design Info Across Design Team Members (recommend improvements to LandXML.org)
Geometric Design:
Alignment
Pavement section
Superelevation
Cross sections
Geometrics
Surveyor
Bridge
Hydraulics
Utility
Right-of-Way
Traffic

24. TransXML Gaps and Opportunities Survey/Design – Best Opportunities
Pay Item Information from Design to Construction (expand on aecXML Infrastructure)
Project Design
Design Estimate
Pay Items
Units of Measure
Quantities
Prices
Standard
Pay Items
Final Plans

25. TransXML Gaps and Opportunities Survey/Design – Best Opportunities
Area Feature Support (LandXML- parcels, GML)
Wetlands
Inventory
ROW
Constraints
Soils
Preliminary
Design
Land Use
Flood
Plains
Hazardous
Materials

26. TransXML Gaps and Opportunities Construction/Materials – Best Opportunities
Publish Construction Status to Stakeholders
Agency Web Page
Project Status
Project Description
Location
% Complete ($)
% Complete (Time)
% Complete (Work)
Milestones
Traffic Restrictions
Construction
Management
System
Stakeholder Reports
(e.g. utilities, RR,
regulatory bodies)

27. Liquidated Damages Rate
TransXML Gaps and Opportunities Construction/Materials – Best Opportunities
Bid Package Preparation
Bid Package
Location
Work Type
Vendor Requirements
Completion Date
Liquidated Damages Rate
Pay Items & Quantities
Web
Browser
Contractor
Bidding Systems
Agency
Management
Systems

28. TransXML Gaps and Opportunities Construction/Materials – Best Opportunities
Track Quantities & Materials Used and Tested
Project Engineer
Progress
Reporting
Field Data
Collection
Systems
Installed Quantities
Pay Item Quantities
Materials
Material Test Results
Placement Location
Material Samples
Tests Performed
Test Outcomes
Laboratory
Systems
Progress Payment
System

29. TransXML Gaps and Opportunities Bridge Structures – Best Opportunities
Bridge Analysis/Design
Bridge Structure
Bridge Description
Analysis Results
Structural
Analysis/Design
Systems
Load Rating
Systems

30. TransXML Gaps and Opportunities Safety – Best Opportunities
Crash Record
Crash Record
MMUCC crash elements
MMUCC linked elements
Other
Crash Reports
Crash Data
Collection Systems
Crash Data
Repositories
Crash Data
Validation Systems

31. TransXML Gaps and Opportunities Safety – Best Opportunities
Highway Safety Analysis Schema
Highway Safety
Characteristics
Geometrics
Safety Hardware
Roadside
Traffic
Other
Crash Data
Collection Systems
Highway Data
Repositories
Safety Analysis
Tools
Crash Data
Validation Systems

32. Potential Use of TransXML
Loose coupling
Direct import/export
Use as base for new, extended XML schemas

33. Use of TransXML Schemas: Loose Coupling
Existing Applications
Existing Import/Export Format
Transformation Programs (XSLT)
TransXML

34. Phase II Status GML Experiment For each schema area:
investigation of the use of elements and structure for XML schema encoding in TransXML – completed
For each schema area:
Startup – post, notify, request - completed
Initial input – scope, resources – completed
UML modeling, review – in progress – comments now requested through August 31, 2005
XML schema development, review –Sept-Oct
Application development – Oct-Nov

35. Currently In Progress…
UML Modeling
Graphical and precise representation of information to be included in TransXML
Primary means of getting agreement on data requirements
Work out issues BEFORE XML encoding

36. UML Example – Project Construction Status

37. TransXML GML Experiment GML Overview
Geography Mark-up Language – Open XMLstandard for geospatial information exchange
GML is XML – fully W3C compliant
Stewardship being transferred from OGC to ISO (19136)
GML provides XML elements for:
Objects (real-world entities with no geospatial properties)
Features (real-world entities with geospatial properties)
Geometries (e.g. points, lines, surfaces, curves)
Topologies (e.g. nodes & edges for network representation)
Spatial and temporal reference systems
Units of measure
Measurements/Observations from cameras/sensors

38. TransXML GML Experiment Why look at GML?
TransXML’s goal is to provide a foundation for XML schema development in transportation:
Building blocks (units of measure, location, etc.)
Rules for schema development – consistent naming conventions and use of XML constructs
A consistent structure will make TransXML easier to use and understand
XML is very flexible – minimal structure is imposed
One XML schema is not necessarily compatible with another
GML could be used to provide this consistent structure – designed to provide a foundation for application schemas
Building on an existing solid foundation is preferable to inventing a new “bare bones” framework for TransXML

39. TransXML GML Experiment What was done?
Developed UML Model for Construction Project Stakeout
Included entities with and without spatial attributes
Developed GML and “vanilla” XML schemas to represent this content
Both imported an external schema element from aecXML
Developed sample instance documents
Developed eXtensible Stylesheet Language (.xsl) documents for each to produce reports
Compared complexity, ease of development and file sizes

40. TransXML GML Experiment Provided Answers to Common Concerns - 1
GML isn’t XML; it is some other language
GML is in fact W3C compliant XML – XML Spy was used to develop GML schemas and parse GML instance documents
GML is only good for geospatial information; why is a geospatial language applicable to engineering data?
GML’s rules for schema development provide valuable structure – regardless of the schema content. GML can be used for non-geospatial information. The experiment included a pay-item element example of this.
Won’t using GML make it more difficult to integrate other, existing XML schema elements?
Existing schema elements can be imported into a GML-based XML schema. The experiment provided an example of importing aecXML elements.

41. TransXML GML Experiment Provided Answers to Common Concerns - 2
Does this mean vendors supporting LandXML and aecXML will have to rewrite their software import and export routines?
TransXML will not be replacing LandXML, but rather working through LandXML.org to suggest enhancements to the LandXML schema
TransXML will rewrite aecXML Infrastructure, but this existing schema is not widely used so the impacts will be minimal. MnDOT is the primary user and the panel representative supports use of GML.
Would using GML imply the need for a major rewrite of the AASHTOWare Virtis/Opis XML reporting tool?
No – minimal changes would be required in the XML instance documents produced by V/O. An XSLT transform could be written to provide translation between TransXML bridge and V/O XML.

42. TransXML GML Experiment Provided Answers to Common Concerns - 3
If TransXML is based on GML, would all TransXML users need to join the OGC?
No – GML is in the process of becoming an ISO standard, and will be maintained through that organization.
Does a choice of GML imply that we would give stewardship for TransXML to the GML stewardship organization?
No – All TransXML elements would be maintained within whatever organization is responsible for TransXML stewardship. TransXML would not need to maintain the primitive GML elements.

43. TransXML GML Experiment Answers to Common Concerns - 4
GML’s geometries lack the precision required for design data
True – But TransXML does not need to use the parts of GML that do not meet its schema requirements. If a more precise geometry element is required, it would be written within TransXML
Wouldn’t GML impose too much overhead and complexity on TransXML schemas and negatively impact their acceptance?
The latest version of GML allows you to include only those parts of GML that are needed for a particular application schema.
The GML experiment showed that GML instance documents have a few additional tags than the “vanilla” XML documents but they are easier to read due to the strict structure imposed.

44. Virtis/Opis GML Example – Schema Fragment
<!-- Material Type -->
<xs:complexType name="MaterialType">
<xs:complexContent>
<xs:extension base="gml:AbstractGMLType">
<xs:sequence>
<xs:element name="Name" type="xs:string"/>
</xs:sequence>
</xs:extension>
</xs:complexContent>
</xs:complexType>
<!-- Reinforcing Steel Material Type -->
<xs:complexType name="Reinforcing_Steel_MateriallType">
<xs:extension base="MaterialType">
<xs:element name="Yield_Strength" type="xs:decimal"/>
<xs:element name="Yield_Strength_UNITS" type="xs:string"/>

45. Virtis/Opis GML Example – XML Fragment
<Reinforcing_Steel_Material>
<Name>Grade 60</Name> <Yield_Strength>60.000</Yield_Strength> <Yield_Strength_UNITS>ksi</Yield_Strength_UNITS>
</Reinforcing_Steel_Material>

46. TransXML Stewardship Role and Functions
Help Transportation Organizations to Reap the Benefits
Technical assistance for schema implementation
Ensure that implementation experience is used to improve schema and expand base of sample applications
Serve as Focal Point for Continued Progress
Update and enhance initial set of TransXML schemas based on stakeholder input
Develop additional schema & sample applications
Serve as Champion
Promote umbrella framework for transportation XML schemas to avoid inconsistent and overlapping efforts
Liaison with stakeholder communities, conference presentations

47. Getting Involved To get involved: Go to www.TransXML.org Register!
Join working groups
Alert community to relevant resources and efforts
Review and comment
Submit schema for consideration/incorporation