Semisequicentennial Transportation Conference Proceedings
May 1996, Iowa State University, Ames, Iowa

The Evolving Role of Standards in Transportation System Design

Vincent P. Pearce

AlliedSignal Technical Services Corp.,
One Bendix Road,
Columbia, Maryland 21045-1897.

Standards are critical to achieving a satisfactory transportation infrastructure (both vehicle and roadway) and have shaped the direction of the transportation industry since its inception. The purposes for standards remain much the same as they have been for close to a century, but the level at which they are specified and the organizations involved in their development have changed. Government mandating of standards is increasingly being replaced by governmental support of industry-developed standards. The globalization of the transportation industry has also affected the outlook on standards, and thereby our approach to their development and enforcement. The standards process, content, and outlook continue to evolve as the transportation industry and traveler needs demand. Key words: standards, transportation, ITS.


Standards have always played an important role in the design of both in-vehicle and infrastructure transportation systems. The agreement upon basic standards supported the development of a national railway system utilizing a common gauge, and thereby seamless cross-country transportation of passengers and freight.

The reliance upon standards is based upon several needs. There is a significant need for compatibility among transportation systems, whether that is as simple as standardized rail shape, size, and width of separation, or as challenging as a single frequency, transmission protocol, and message structure for radiofrequency automatic vehicle identification tags utilized for electronic toll collection.

A second need for standards is to assure quality in transportation products and systems. For many years, the best examples of this were the standards highway departments used in specifying paving material, paints, and structural supports. As vehicle quality has become a more critical competitive factor, the use of quality standards has become equally pervasive inside the vehicle as it is in the transportation infrastructure. Over the last several years, the automotive industry has developed its own version of the widely applied ISO 9000 process quality certification, QS 9000, to assure that the goods incorporated into the vehicle (from passenger car to class 8 heavy vehicle) meet at least a minimal acceptable standard for product quality.

A third driving force supporting standards is the need for safety. Although many vehicle safety standards have arrived in the form of regulations (5 mph bumpers, side-guard impact protection), safety standards have also been critical in transportation infrastructure, with examples such as breakaway signposts, guardrail placement and configuration, work zone safety procedures, and defined illumination levels on heavily traveled roadways.


Standards have been developed in a variety of ways. Some have been adopted from commercial standards (either directly, or with modification); others have been developed within the highway departments, or at a federal level (FMVSS). The developing authorities may have been government (state DOTs, NHTSA), government associations (such as AASHTO), or industry groups (such as NEMA and ITE). As the transportation market has become one of global proportions, international organizations (such as ISO and the European Union) have become involved in standards definition and implementation. New types of organizations have also become involved, such as the IEEE, due to the increasingly technical (electronic) content of new standards. Even the long-term participants in transportation standards development, such as SAE, are spending an increasing amount of time focused on technology-based standards.

Many of the earliest and most critical standards developed through legislation, at either the federal or state/local level. In 1905, the first bill was introduced in Congress (unsuccessfully) to regulate how vehicles operated on streets and highways. Ensuing major federal programs have greatly influenced the direction of transportation infrastructure. The Federal Road Aid Act of 1916 set design criteria for key roadways and provided for 50 percent matching federal funds for their construction. The Federal Highway Act of 1938 took a next step toward six intercoastal interstate highways. Almost two decades later the Federal Highway Act of 1956 authorized construction of 66,000 km of interstate roads. Presidential Highway Safety Conferences in 1946 and again in 1954 worked toward establishment of goals and methods for creation of a safe transportation network. A critical step was the 1937 publication of the first Manual on Uniform Traffic Devices to standardize, among other things, roadway sign appearance and content.

State and local government have been equally vigorous participants in setting transportation standards. In 1908, Toledo and Detroit placed manually operated red/green signals at intersections. By 1919, Detroit's system had evolved to a timed red-yellow-green system to control traffic in four directions. By 1950, each state had created a highway safety agency. A decade later the role chosen by state/local government had further evolved, with Wisconsin becoming the first state to mandate that vehicles sold within the state have seatbelts installed. It would be almost 30 more years before states began mandating the use of seatbelts by vehicle occupants, but such a trend would sweep the nation once it began to take hold. Even as early as 1977, Tennessee began to require use of appropriate child restraints in passenger vehicles.


As transportation systems become more complex (and less directly measurable, such as with the software in an engine control unit), the nature of standards continues to change to fit the new requirements, the new types of systems (containing more electronics and software), and the interagency and international environment in which they must operate. Where an early standard may have dealt with a physical interface (or may have only defined performance, leaving the methodology up to the manufacturer), more recent transportation standards work at a more detailed level, and require more specific measures within the transportation product or system.

The standards process in the emerging field of Intelligent Transportation Systems (ITS) is an example of the state of transportation standards development today. The first ITS standards emerged in a hybrid situation: in-vehicle standards, but for use in government-owned vehicles. In 1994, the Intelligent Transportation Society of America recognized those among its membership who had achieved the first ITS-driven (SAE) standard, for the internal connection of subsystems within transit vehicles (commonly referred to as the "bus bus").

The involvement of the federal government has been critical in aiding the efforts and strengthening the resolve of industry in creation of the first intelligent transportation infrastructure standard (still in draft form), the National Traffic Control/ITS Communications Protocol (NTCIP) being developed by NEMA. In addition to providing needed funding (to supplement the normally slow progress of volunteer-dependent standards development), FHWA has also sponsored a joint industry-government steering group to assure that the resulting standard both meets the user community's needs and is practical for industry to apply. More recently, USDOT has selected five Standards Development Organizations to be funded to accelerate the development of necessary ITS standards.

ITS has set a somewhat new direction by choosing to establish a national systems architecture during the early years of the industry. The (partially federally-funded) architecture program was established, however, not to create a mandatory system design, but rather to identify and promote standards at the interfaces between portions of a total ITS system. Thus, for example, the architecture will not mandate a single technology or design for a variable message sign, but will identify and promote use of a standard (the aforementioned NTCIP) between the VMS and the control center responsible for it. The architecture has been developed by four teams (later reduced to two), each under the leadership of a different recognized aerospace-defense firm, but containing a variety of members of the transportation user community. An outreach program for the architecture effort, resulting in hundreds of national and local meetings, presentations, and reviews has resulted in significant input and guidance for the architecture teams (and their program manager, the Jet Propulsion Laboratory), and in above-average support for the concept of a single national architecture. Much of the later-stage effort of the architecture program has been aimed at identifying standards needs and priorities, and in tying the standards process to the architecture program's results.

ITS has been faced with the need for several overarching standards. The standards have typically addressed areas utilized both inside the vehicle and by the transportation infrastructure. Of particular importance has been standards for identifying "where I am," more formally referred to as spatial database reference standards. Consistent with the need to promote development and innovation within the industry, the focus has been on a common standard for transfer of the information, rather than for how it is used within a system. Thus, multiple developers and manufacturers can use their own formats within their devices, but can exchange information through a common format.

Consistent with the direction taken by much of government, ITS has broadly adopted commercial standards and standards created by other industries. Since ITS infrastructure is computing- and communications-intensive, adoption of standards such as the TCP-IP communications protocol and IEEE 802.3 Local Area Network standard has been commonplace. ITS has also retained many of the pre-existing transportation industry standards in areas it has "absorbed," such as those for field equipment controllers (type 170 and NEMA TS1), the installation of inductive vehicle loop detectors, or for poles on which CCTV cameras are mounted.

Only a few years after its recognition as a distinct industry, ITS is heavily involved in international standards development as well. In this situation, SAE serves as the convener of the ISO ITS Technical Committee, with ANSI responsible for US participation. ISO and CEN (the European Union's pre-existing counterpart) have mutually defined areas for standards effort, and have divided the lot, with one agency or the other taking the lead role in each area.


The need (and demand) for standards in transportation continues to exist, perhaps at its greatest level ever. While the traveler no longer faces the confusion of differing road sign shapes, sizes, messages, and placement as he/she motors from one state to the next, the new challenges of electronic map database compatibility (for the same motorist's onboard vehicle navigation system) create a demand for appropriate standards. Both traditional transportation standards-setting bodies and new standards organizations are involved in their development. Government performs in multiple roles, often as facilitator rather than regulator. Standards are influenced by the need for global competitiveness. The role of standards in transportation continues to be an important one, with new and intelligent ways being applied to achieve the overarching goals of moving people and goods across the nation and around the world.

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