U.S. DOT Releases New Standards Fact Sheets
May 22, 2006
The U.S. Department of Transportation (DOT) released five new "plain English" standards fact sheets in the areas of traffic management, transportation management, center-to-center naming conventions, field management stations and ATIS message standards.
Fact sheets are now available for:
AASHTO-ITE 2.1 - Standards for Traffic Management Center-to-Center contains both a functional level data dictionary and a message set and is designed to be independent of any specific communications protocol. The data dictionary defines a set of data elements (DEs) necessary to support data exchange within and among traffic management systems. Specifically, it provides meta-attributes for each DE including definitions (semantics) and specific format (syntax).
According to DOT, the data dictionary and message set included in the standard were based on the logical and physical information flows supporting the "manage traffic" function as described in the National ITS Architecture. The standards consist of two volumes, including:
- Volume I: Concept of Operations and Requirements
- Volume II/Companion Annexes: Message Sets (in ASN.1 and XML formats) and Data Dictionary
A database format of the messages and data elements is also available.
The messages and DEs identified in this standard and formatted in ASN.1 (Abstract Syntax Notation One) and XML (eXtensible Markup Language) are exchanged between a traffic management center and other centers, such as other traffic management centers, maintenance and construction management centers, transit management centers, traveler information providers, emergency management centers, toll administration, event promoters, data archives, the media and the weather service.
The following ITS standards are related and should be considered when using this standard:
NTCIP 1103 - Transportation Management Protocols defines a set of rules and services for exchanging transportation management information between transportation management applications and equipment in an interoperable manner. The Transportation Management Protocols (TMP) are interoperable with the Internet-standard Simple Network Management Protocol (SNMP) and extend SNMP to provide for the needs of the transportation community.
The transportation community needs protocols that are simple, flexible and efficient. In many cases these three requirements are at odds with each other; thus this TMP standard defines two other protocols, Simple Fixed Message Protocol (SFMP) and Simple Transportation Management Protocol (STMP) along with SNMP to ensure that they work together. According to DOT, this is accomplished by using the objects defined in NTCIP 1103.
The objects defined in the data construct contain information, commands and responses that must be understood by the devices at both ends of the communications channel. The NTCIP development effort also needed a way to specify component objects at run-time as opposed to statically in a management information base (MIB).
The following ITS standards should be considered when using this standard:
The following set of standards and documents, while not part of the ITS standards, should also be considered when using this standard:
NTCIP 1104 - Center-to-Center Naming Convention Specification provides a standard way for transportation management centers to uniquely name entities for which data are exchanged with other centers. Unique names are important to avoid ambiguity and confusion when information is exchanged between centers.
According to DOT, communications between a transportation management center's central computer and other centers requires a common naming hierarchy for identifying entities such as centers, field devices, incidents, personnel and vehicles. The naming structure defines the order of specific fields used to uniquely name a given ITS entity. Further standardization within a region is necessary for the exact field name definition within the naming hierarchy.
The following ITS standards should be considered when using this standard:
NTCIP 1210 - Field Management Stations (FMS) - Part 1: Object Definitions for Signal System Masters provides the vocabulary (commands, responses and information) necessary for traffic management and operations personnel to control, manage and monitor signal system masters. The standard also includes a protocol requirements list (PRL) and a requirements traceability matrix providing object conformity information.
The following ITS standards and documents are related and should be considered when using this standard:
The following standards and documents, while not part of the ITS standards, should also be considered when using this standard:
SAE J2630 - Converting ATIS Message Standards from ASN.1 to XML is used to develop a stand-alone XML schema that is fully consistent with an existing ASN.1 information model. Although the rules defined in SAE J2630 were initially developed in order to produce an XML schema for SAE J2354, other ITS message set developers may choose to use these rules to produce XML schemas from their existing ASN.1 definitions.
According to DOT, the standard was developed specifically to support conversion of the ASN.1 used in the SAE J2354 message set into a stand-alone XML schema for traveler information. To ensure that the translations could be used successfully for other ITS Standards, the IEEE 1512 standards family - Standards for Traffic Management Center-to-Center Communications and Transit Communications Interface Protocols (TCIP) message sets were also considered during development of SAE J2630. This standard is distinct from other standards that have been developed that define XML Encoding Rules (XER) for ASN.1 and rules for mapping XML schemas into ASN.1.
The following ITS standards are related and should be considered when using this family of standards:
The following standards and documents, while not part of the ITS standards, should also be considered when using this standard:
Source: U.S. Department of Transportation ITS Standards Program.