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NTCIP 1204 - Object Definitions for Environmental Sensor Stations (ESS)

This Fact Sheet was written on 9/18/2009. The status of the standard at the time was: Published in September 1998, version 2 approved in 2006, and minor revisions were approved and published in 2008. Version 3 was approved in January 2008 as a recommended standard and balloting occurred, but version 3 has not been published.

This Fact Sheet was written on September 18, 2009. The status of the standard at the time was: Published in May 2008.

This Fact Sheet was last verified on September 18, 2009

 Check the ITS Standards Search to see if there has been subsequent development activity.


The National Transportation Communications for Intelligent Transportation System (ITS) Protocol (NTCIP) is a family of standards that provides both the rules for communicating (called protocols) and the vocabulary (called objects) necessary to allow electronic roadside equipment from different manufacturers to operate with each other as a system. The NTCIP is the first set of standards for the transportation industry that allows transportation systems to be built using a "mix and match" approach with equipment from different manufacturers. Therefore, NTCIP standards reduce the need for reliance on specific equipment vendors and customized one-of-a-kind software. To assure both manufacturer and user community support, NTCIP is a joint product of the National Electronics Manufacturers Association (NEMA), the American Association of State Highway and Transportation Officials (AASHTO), and the Institute of Transportation Engineers (ITE). More information concerning the NTCIP family of standards and their related documents is available in the NTCIP 9001 - NTCIP Guide, available on-line at (

Human communications relies on a vocabulary of words, each defined with a fixed meaning and spelling that are understood by the members of the conversation group. Computers have a similar vocabulary, called "objects" in the NTCIP standards. These objects define all possible commands, responses and information that may be exchanged among microprocessor-controlled electronic equipment, traffic management systems (which could include central computers housed in a center or portable computers, e.g. laptops), and by extension, their human operators. The NTCIP groups these objects by subject material (e.g., environmental sensor stations) and calls these groupings "object definitions." The objects defined in this standard allow an operator to configure, control, and monitor an environmental sensor station (ESS).

What are these standards for?

NTCIP 1204 - Object Definitions for Environmental Sensor Stations (ESS), provides the vocabulary - commands, responses, and information - necessary for the management of environmental sensor stations, including road weather information systems (RWIS), air quality monitoring systems, and pavement treatment systems (PTS).

This standard defines those objects used to describe ambient conditions (including air pressure, wind, temperature, humidity, precipitation, solar radiation, visibility, water level, and air quality) and pavement conditions (including surface and subsurface temperature, icing, moisture, treatment, etc.), and to manage pavement treatment systems (e.g., anti-icing or de-icing sprayers).

Who uses them?

NTCIP 1204 - Object Definitions for Environmental Sensor Stations (ESS) should be used by transportation and traffic engineers involved with the design, specification, selection, procurement and installation, testing, operation, and maintenance of RWIS, air quality monitoring systems, or PTS. ITS product hardware and software designers and application (computer program) developers should find this standard especially relevant to their efforts.

How are they used?

NTCIP 1204 - Object Definitions for Environmental Sensor Stations (ESS) defines a vocabulary of "objects" used to assure that the transportation management systems and electronic RWIS, air quality monitoring systems, or PTS "speak" a common language. A message must be understood by the device it was intended for, and equally important, it must not be misunderstood or misinterpreted by another device on the same network. Object definitions unambiguously define the content, terminology, value, and format of commands, responses, and information affecting communications with RWIS, air quality monitoring systems, or PTS.

NTCIP 1204 includes a Protocol Requirements List, which identifies user needs and functionalities, and relates them to requirements that must be fulfilled by the elements of the standard. The user should review the PRL to determine which functionalities are desired for a project. Those functionalities, as checked on the PRL, will identify which requirements must be fulfilled. The standard also includes a Requirements Traceability Matrix, which shows which objects in the standard fulfill the requirements identified in the PRL.

This standard must be used with one of the NTCIP communications profiles (see related NTCIP documents below) which provide the communications channel for information transfer between devices. It must also be used with the NTCIP Global Object Definitions (NTCIP 1201), which provides the glossary of common object definitions used by multiple NTCIP devices.


Communication between a traffic management system’s central computer and environmental sensor stations is accomplished by using the objects defined in this standard, NTCIP 1204 - Object Definitions for Environmental Sensor Stations (ESS). These objects define the information, commands and responses that must be understood by the devices at both ends of the communications channel. This standard defines objects across three major areas of operation: management of ESS equipment (monitoring power, chemical dispersion, etc.), management of sensor functions (monitoring weather conditions, pavement conditions, subsurface conditions, air quality, etc.), and management of Pavement Treatment Systems (configuration, monitoring, and activation of stationary and mobile anti-icing or de-icing chemical spray systems). Version 2 of this standard was developed using an established systems engineering process and includes the concept of operations, functional requirements, interface specifications and a requirements traceability matrix.

Related documents

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:

How to obtain Standards
American Association of State Highway and Transportation Officials
Institute of Transportation Engineers
Association of Electrical and Medical Imaging Equipment Manufacturers (NEMA), formerly known as National Electrical Manufacturers Association