Glossary

Glossary Term	Definition
Advanced Traffic Management System (ATMS)	An array of human, hardware, and software components designed to monitor, control, and manage traffic on streets and highways. This includes those used for surveillance and control of traffic on freeways and arterial routes, detection of roadway traffic flow and incidents, and communication with vehicles, traffic management centers, and organizations responsible for traffic management.
Annual Average Daily Traffic (AADT)	The estimate of the typical daily traffic on a road segment for each day of the week for one year.
ATR count	The base traffic count recorded by an Automatic Traffic Recorder (ATR) devise.
Automatic Traffic Recorder (ATR)	A device that records the continuous passage across a given section of roadway, 24 hours a day, 7 days a week, and 365 days a year.
Average Daily Traffic (ADT)	The total traffic volume during a given time period (more than a day and less than a year), divided by the number of days in that time period.
Average Day of Month (ADOM)	The estimate of the average daily traffic on the average day of the month.
Base Count	A traffic count that has not been adjusted for axle factors or seasonal effects.
Base Data	The unedited and unadjusted measurements of traffic volume, vehicle classification, and vehicle or axle weight.
Collector	Roadways that provide both land access service and traffic circulation within residential neighborhoods, commercial and industrial areas, and downtown city centers. Collectors connect local roads and streets with arterials, and provide less mobility than arterials at lower speeds and for a shorter distance.
Count	The data collected as a result of measuring and recording traffic characteristics such as vehicle volume, classifications, speed, weight, or a combination of these characteristics.
Count Period	The period of time with a beginning and ending date over which traffic characteristics are measured.
Count Type	The traffic characteristic being measured, the measurement device, and time period.
County Coverage Map	A map displaying the traffic count totals for each county in the state.
Coverage Count	A traffic count taken as part of the requirement for system-level estimates of traffic. The count is typically short-term, and may be volume, classification, or Weight-in-Motion (WIM).
Daily Vehicle Miles Traveled (DVMT)	The Annual Average Daily Traffic (AADT) multiplied by the length of the road segment.
D-Factor	The value is computed by dividing the volume measured in the direction of dominant flow by the total high hour volume and multiplying by 100. "NA" indicates directional data is not available.
Duration	The time period over which traffic is monitored.
Federal Highway Administration (FHWA)	The federal agency responsible for providing funding and guidance to various transportation departments throughout the country.
Frequency	The cycle over which traffic data is collected at a location.
Functional Classification (FC)	The grouping of streets and highways into classes, or systems. According to the character of service they are intended to provide. The recognition that individual roads do not serve travel independently and most travel involves movement through a network of roads is basic to functional classification.
Geographic Information System (GIS)	A method of storing, analyzing, and displaying spatial data.
Highway Performance Monitoring System (HPMS)	A federally mandated data reporting system for all roads except local.
Intersection Counts	Traffic counts taken at an intersection to study the flow of vehicles through the intersection. Generally, straight movements are recorded with counters, and turning movements are either taken manually or in combination with counters.
Interstate	Roadways that consist of the designated freeway routes meeting the Interstate geometric and construction standards for future traffic. The Interstate System is the highest classification of arterial roads and streets and provides the highest level of mobility, at the highest speed, for a long uninterrupted distance.
K-Factor	The value is computed by dividing the peak hour volume by the Average Annual Daily Traffic (AADT) for the station and multiplying by 100.
Local	Roadways that provide a high level of access to abutting land, but limited mobility.
Local Road Sample Map	A map showing the traffic count totals on various local roads throughout the state.
Loop Detector	A detector that senses the passage or presence of a vehicle near the sensor.
Manual Counts	The measurement of traffic characteristics based on human observation, which may or may not be electronically recorded.
Mechanical Counts	The measurement of traffic characteristics by sensors and electronic recording of the measurements, independent of human observations.
National Highway System (NHS)	A designated system of highways of National Significance mandated under the Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991. The purpose of the NHS is to provide an interconnected system of principal arterial routes to serve major population centers, airports, and public transportation facilities, to meet national defense requirements and to serve interstate and interregional travel.
Other Principal Arterials	Roadways that consist of limited-access freeways, multi-lane highways, and other important highways supplementing the Interstate System that connect the Nation's principal urbanized areas, cities, and industrial centers; serve the national defense; and connect at suitable border points with routes of continental importance.
Peak Period	The highest period of traffic flow during the AM and PM time period.
Permanent Count Station	The specific location where an Automatic Traffic Recorder (ATR) is placed.
Project-Related Count	A traffic count collected for supporting a roadway or bridge project.
RCLink	The 10-digit identification number that is assigned to the road. The 1st - 3rd characters are the county Federal Information Processing Standards (FIPS) identification (ID) number. The 4th character is the route type number. The 5th - 8th characters are the state route number. The 9th and 10th characters are the state route suffix.
Rural	Areas that are outside the boundaries of small urban and urbanized areas.
Small Urban	Areas that have a population of 5,000 or more, but are not in an urbanized area.
Special Count	A traffic count collected in response to a request for traffic information, not included as part of the coverage or project-related count plan.
Special Purpose Count	A traffic count collected for the specific purpose of better understanding traffic flow characteristics at predetermined sections of roadway. These may include studying the effects of traffic accidents, roadway closures, or traffic re-routing.
Strategic Highway Research Program (SHRP)	A five-year program for pavement and operations research funded by Congress and managed through the National Academy of Sciences. One of the four research areas, long-term Pavement Performance, is planned as a 20-year program.
Traffic Monitoring System for Highways (TMS/H)	A systematic process for the collection, analysis, summary, and retention of highway related person and vehicular traffic data, on public highways and streets.
Traffic Program	The collection, editing, summation, reporting, and analysis of traffic volume, classification, and weight data.
Travel Time	The amount of time a vehicle spends traversing a route or route segment. Average speed can be computed by taking the length of the highway or street segment under construction and dividing it by the average travel time for that segment.
Urban	Areas that have a population 5,000 or more and are designed as urbanized areas by the Bureau of the Census.
Vehicle Classification	The measurement, summarization, and reporting of traffic volume by vehicle type and axle configuration.
Vehicle Miles Traveled (VMT)	The vehicle movement on a specific road segment multiplied by the length of the road segment, reported in the form of daily and annual VMT.
Weigh-in-Motion (WIM)	The process of estimating a moving vehicle's static gross weight and the portion of that weight that is carried by each wheel, axle, or axle or combination thereof, by measurement and analysis of dynamic forces applied by its tires to a measuring device.

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