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1 SUMMARY TransXML: XML Schemas for Exchange of Transportation Data Project Overview NCHRP Project 20-64 was undertaken to develop TransXML--a family of transportation data exchange formats using XML--the eXtensible Markup Language. These data exchange formats are intended to make it easier for transportation agencies to share information within and across the different stages of the transportation facility life cycle--spanning planning, design, con- struction, maintenance, and operations. XML is being used in a variety of other industries to enable data sharing. However, XML in and of itself is not a "silver bullet"; its value depends on getting agreement on data exchange formats from data owners, data users and software vendors. TransXML responds to the urgent need for the transportation community to work together on common data exchange formats. TransXML provides an open, vendor-neutral format for stor- ing, exchanging, and archiving data. It therefore allows agencies to have more control over their data, and to get more value out of it over the long haul. The justification for the TransXML project was to save agencies money. Currently, countless hours are wasted reentering or recreating information that already exists in electronic form. Data quality suffers in the process, and additional resources must be invested to ensure that data are correct with each transfer. Some transportation agencies have already recognized the value of XML, and are developing their own XML formats or "schemas" to facilitate data exchange across applications. A collective, broad-based approach to this problem reduces the need for multiple efforts of this nature. More importantly, it enables and encourages software vendors to build in standard data import and export features consistent with the agreed-upon formats. This will give agencies more choices, and will reduce the costs of configuring and implementing new applica- tions. TransXML also provides a way for agencies to archive their valuable data in a text format that is human-readable and independent from the software used to create and store it. Scope and Products NCHRP Project 20-64 was designed to start development of TransXML by focusing on four transportation business areas: (1) Survey/Roadway Design, (2) Transportation Construction/ Materials, (3) Highway Bridge Structures, and (4) Transportation Safety. XML Schemas were developed within each of these areas, along with sample applications that demonstrate how the schemas can be used. The initial set of TransXML schemas are described in Table ES-1. For each business area, key stakeholders were identified and input was solicited via e-mail and via a collaborative website established for the project. Key milestones in the project were as follows: Definition of the scope for schemas based on an analysis of data exchange needs and gaps, Development of data models for each schema using Unified Modeling Language (UML) class diagrams,

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2 Table ES-1. TransXML schemas. Business Area Schemas Survey/Roadway Design Area Features (AF) Schema Allows data from GIS to be overlaid on design drawings in CAD systems. Geometric Roadway Design (GRD) Subset of LandXML adopted into TransXML allows for sharing of roadway alignment, cross sections, geometry across members of a design team, between designer and surveyor, and from design into machine controlled excavation equipment. Design Project (DP) Allows design project pay item data to be exchanged across design, cost estimation and bid preparation systems. Transportation Construction/ Bid Package (BP) Supports exchange of construction bid Materials package data between agency systems and contractor bid preparation software. Construction Progress (CP) Supports exchange of information about partial pay item quantities placed from field data collection systems to construction management systems. Materials Sampling and Testing (MST) Allows exchange of construction site installed quantities and materials used and tested information from field data collection systems to laboratory systems, central construction progress tracking and contractor payment systems. Project Construction Status (PCS) Allows exchange of construction project status information from construction management systems to stakeholder information systems (e.g., project web sites). Highway Bridge Structures Bridge Design and Analysis (BDA) Allows for analysis of the same structure in multiple structural analysis software packages. Transportation Safety Crash Report (CR) Allows exchange and sharing of crash records data. TransXML adopted the NHTSA/JusticeXML crash records XML Schema that is based on the Model Minimum Uniform Crash Criteria (MMUCC). Highway Information Safety Analysis (HISA) Allows for exchange of highway information between inventory systems and safety analysis software. All Linear Referencing (LR) An XML schema for linear referencing information consistent with ISO 19133 used by the other TransXML schemas. Selection of the Geography Markup Language (GML) to provide a consistent framework for XML encoding across the new XML schemas to be developed, and Development of the XML schemas and sample applications. Future of TransXML NCHRP Project 20-64 has provided an initial set of TransXML schemas and has established an umbrella framework for development of additional schemas. In order to reap the full bene- fits of this work, there is a need to educate potential users about how to use the schemas, and to provide technical assistance for agencies and vendors choosing to modify their systems to read and write data in TransXML format. There is also a need to extend the current set of schemas to address other data exchange needs both within and outside of the four initial TransXML busi- ness areas.

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3 Future efforts should recognize the key lessons learned during the course of this project: The TransXML concept of a broad umbrella for a set of interrelated transportation data exchange formats has the advantage of supporting interoperability of data across different business processes and life-cycle phases of transportation facilities. However, this umbrella concept creates challenges in that there are several distinct stakeholder communities within transportation. This means that extra effort is needed to (a) provide sufficient depth of com- munication and technical understanding for multiple different stakeholder groups, (b) ensure technical consistency and coordination across individual schema, and (c) maintain broad interest and support for the project. For TransXML to succeed, there needs to be a substantial and sustained effort to raise aware- ness of the project. Significant resources must be allocated for communication with stake- holders--through multiple channels--in order to ensure that the XML schemas are widely understood and perceived to have clear value. Resources must be devoted to coordinate TransXML efforts with related standards efforts since TransXML touches many areas where schema and standards already exist or are under devel- opment. This will maximize the potential for synergies and harmonization across efforts. Based on these lessons learned, a model for future TransXML stewardship was developed, including a mission statement and a set of recommended functions and roles. Several different stewardship models were evaluated based on an examination of other XML efforts and consid- eration of key criteria--including neutrality, stability, agility, technical expertise, marketing capa- bility, and administrative infrastructure. Because it is critical to maintain momentum for the TransXML project while a more perma- nent stewardship arrangement is being established, the project team recommends that AASHTO take on temporary stewardship for the project for a period of up to 12 months. During this tran- sition period, AASHTO or a designated contractor would maintain the TransXML website, con- tinue with a skeletal level of outreach and liaison activities, and initiate one or more pooled fund projects to demonstrate implementation of selected TransXML schema. During this time, dis- cussions would be pursued to explore--and ideally obtain commitment for--ongoing sponsor- ship for the project.