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Glossary business processes. Consist of the organized activities car- dom, unpredictable, and transitory events, including vehic- ried out in common to develop and implement SO&M, ular crashes and breakdowns, weather, road construction including scoping, planning, programming and budget- activity, and planned special events. The causes of NRC ing, systems and technology engineering, project develop- together produce about half of total delay and most of the ment, and performance measurement. system unreliability, and they contribute to safety problems. congestion management. The set of highway SO&M actions recurring congestion (RC). The portion of total delay taken to minimize the causes and impacts of congestion, caused by the everyday, predictable delay that occurs from both recurring and nonrecurring. supply-demand imbalance at peak periods. It is addressed effectiveness of NRC strategy application or program. by such strategy applications as ramp metering, signaliza- Refers to the measurable impact of such application on tion, and demand management through pricing. the outcomes of congestion management, specifically in reliability. The major factor affected by NRC, which is, by terms of reduction in delay and improvement in reliabil- virtue of its causes, unpredictable. It is measured by the vari- ity and safety. ation in travel times for identical trips. The lack of pre- institutional architecture. A research term that refers not dictability is what requires drivers to allow extra time to only to organizational characteristics--such as organiza- reach their destinations by a given time. For example, a tional structure, policy/mission, leadership/staff, resources/ driver may allow 30 min for a trip that usually takes 20 min. technology--but also to the prevailing culture and values, strategy applications. The set of known transportation sys- legal framework (including legislative bodies and political tems and operations management conventions related to administration), and partnering relationships among orga- user services directed at the causes of congestion--e.g., nizations, both formal and informal. incident management, work zone traffic control, traveler mainstreaming. Becoming an integral part of core agency information. activities. A mainstreamed concept is widely understood systems operations and management (SO&M). A term and accepted by the agency (as well as its partners and con- applied to a program of ITS infrastructure and related real- stituents) at all levels. It is fully integrated into the agency- time activities targeted at maintaining or improving the wide culture, business processes, budgeting, organization, performance of the existing transportation infrastructure in and staffing. response to the causes of both recurring and nonrecurring nonrecurring congestion (NRC). The portion of congestion delay, disruption, unreliability, and related safety and secu- attributable to traffic delays and disruptions caused by ran- rity problems. 70