This article defines the terminology, abbreviations, and acronyms used throughout our documentation and training content. There are regional and other differences in transit terminology, so this guide establishes a common meaning for all terms.
Transit Abbreviations
| Abbreviations | Definition |
|---|---|
| AA | Automated Announcements |
| ADA | Americans with Disabilities Act |
| ANSA | Automatic Next Stop Annunciation |
| APC |
Automatic Passenger Counters - Sensors located in vehicles that capture passenger boards and alights. |
| APN | Access Point Name |
| APTA | American Public Transportation Association - Not the American Physical Therapy Association |
| ATIS |
Advance Traveler Information System - System that acquires, analyzes, and presents information to assist travelers in planning their trips (i.e. traveling from point A to point B). |
| ATMS | Advanced Transportation Management System |
| AVA | Automatic Voice Announcements |
| AVL | Automatic Vehicle Location |
| BIB |
Bus in a Box - A driver training station used to teach operators and dispatchers how to interact with the system most effectively (Dispatcher screens and Operator MDT). |
| BOB |
Bus On a Board - A training station used for demonstration/ hands-on training usually of Maintenance staff. |
| CAD | Computer Aided Dispatch |
| CAN | Controller Area Network |
| CARSD | Computer-Aided Registration, Scheduling, and Dispatch |
| CCM |
Communications Control Module - An Avail device to control voice communications from vehicles over a private radio network (PRN) or VoIP |
| CMAQ | Congestion Management and Air Quality |
| DIRT | Data Import Reconciliation Tool |
| EA | Emergency Alarm |
| FASTTM |
Follow-on Adoption Support & Training - An Avail department dedicated to supporting Avail customers’ post-project. This group identifies ways to improve operational practices at transit agencies and can also make recommendations for CARS (customer add-on requests/ upgraded features). |
| FHA | Federal Highway Administration |
| FTA | Federal Transit Administration |
| GIS | Geographic Information System |
| GFI | A provider of farebox solutions. Known as GFI® or GFI Genfare between 1980 and 2012. In 2012 the company became SPX Genfare. |
| GPS | Global Positioning System |
| ICD | Interface Control Document |
| IEB |
Interface Expansion Box - Avail term for port expander/interface unit, used by Avail in place or generic term VLU or IVLU. |
| ITS | Intelligent Transportation System |
| IVR | Interactive Voice Response |
| IVLU | In-Vehicle Logic Unit (See IVU) |
| IVU |
In-Vehicle (logic) Unit - Avail term for ruggedized computer. Avail uses this term in place of the generic industry terms VLU or IVLU. |
| KPI | Key Performance Indicator |
| LTR |
Logic Trunk Radio - Provides support for voice and data over one radio. |
| MDC | Mobile Data Computer - See MDT |
| MDT |
Mobile Data Terminal - MDC and MDT can be used interchangeably. MDT is Avail's preferred term. In-vehicle hardware that displays schedule and other information for operators. |
| MTS |
Maintenance Training Station - Used for hands-on training for maintenance staff/ demo installations and troubleshooting strategies. |
| NSA | Next Stop Annunciation System |
| NTD | National Transit Database |
| OEM |
Original Equipment Manufacturer - Avail’s partnership with bus manufacturers – (Gillig, New Flyer, etc.). |
| OOS | Out of Service |
| PDC | Passive Data Collection |
| PENNDOT | Pennsylvania Department of Transportation |
| PRTT | Priority Request To Talk - (on MDC for closed microphone radio systems) |
| PTV | Public Transportation Vehicle |
| RBC | Redundant Base Controller |
| RCU |
Radio Control Unit - An Avail device used to control radio communications from vehicles in a closed mic system. |
| RFID | Radio Frequency Identification |
| RMA | Return Materials Authorization |
| RRB | Release Review Board |
| RTPI | Real-Time Passenger Information |
| RTPIS | Real-Time Passenger Information System |
| RTT |
Request To Talk - On MDC for closed microphone radio systems. |
| TALE | Trigger Action Location Editor |
| TAP | Transit Access Pass |
| TCP |
Transfer Connection Protection - An Avail feature that ensures when a passenger requests a transfer to another route, the transfer will occur without an undue wait. |
| TIDS | Traveler’s Information Data Service |
| TIS | Traveler Information Service |
| TSP | Transit Signal Priority |
| TLC | Technology Leadership Committee |
| USDOT | United States Department of Transportation |
| VHM | Vehicle Health Monitoring |
| VLU | Vehicle Logic Unit - See IVU. |
| WiNG |
Wireless Network Gateway - Proprietary software used in vehicle communications. |
Computer and General Terms
| Term | Definition |
|---|---|
| ACL |
Access Control List A list of access control entries/ the pathway by which object permissions information is distributed (i.e. LAN). |
| AP |
Access Point Location for the gateway device that connects a mobile network and another computer network. |
| API | Application Protocol Interface |
| APN |
Access Point Name A gateway between a mobile network and another computer network. |
| BAFO | Best And Final Offer |
| CAR | Customer Action Request |
| CBT | Computer-Based Training |
| CDR |
Critical Design Review Term used to describe one of the project phases; confirming Avail SE configurations meet customer demand per the contract. |
| CIP | Continued Process Improvement |
| COTS | Commercial Off The Shelf |
| DB | Database |
| DMS | Dynamic Messaging Systems |
| DMZ |
Demilitarized Zone (Outside Firewall) A term used to describe a perimeter network. Its purpose is to increase security for external facing services such as LAN (local area network). |
| DVR | Digital Video Recorder |
| ECP | Engineering Change Proposal |
| ECO | Engineering Change Order |
| ECR | Engineering Change Request |
| ESP |
ESP Services Third-Party Vendor that does vehicle installs. |
| FAT |
Factory Acceptance Testing ITS Implementation project phase whereby testing of the ITS system occurs, typically at Avail. |
| FEW |
Fun Enjoyable Workplace A group of Avail employees dedicated to creating activities and functions throughout each year that impart a sense of community in fun ways among employees. |
| GIS | Geographic Information System |
| GPS | Global Positioning System |
| GUI | Graphical User Interface |
| ICD | Interface Control Document |
| IIS | Internet Information Services |
| IP | Internet Protocol |
| KML |
Keyhole Markup Language Google Earth is one example – Used to identify the latitude and longitude for specific scheduled stop locations. This information is required when creating schedule data (trip patterns for routes- distances from stop to stop). |
| LAN | Local Area Network |
| LTR |
Logic Trunk Radio Provides support for voice and data via radio. |
| MIS | Management Information System |
| NCIC | National Crime Information Center |
| OBD | On Board Diagnostics |
| ODO |
Odometer In-Vehicle device that performs automatic calculation of mileage. |
| PDN | Private Data Network |
| PDR | Preliminary Design Review |
| PM | Project Manager |
| POE | Power Over Ethernet |
| PRN | Private Radio Network |
| RBC | Redundant Base Controller |
| RCU | Radio Control Unit |
| RFID | Radio Frequency Identification |
| RMA | Return Materials Authorization |
| RRB | Release Review Board |
| RWG | Release Working Group |
| SAE | Society of Automotive Engineers |
| SAT |
System Acceptance Test A project phase that includes testing all product components for accuracy and function. |
| SE | System Engineer |
| SIT | System Integration and Testing Team |
| SQL |
Structured Query Language An international standard for database manipulation. |
| SW | Software |
| TCP | Transfer Control Protocol |
| TMS |
The Master Scheduler A software tool of Schedule Masters. |
| TRB | Technology Review Board |
| TWG | Technology Work Group |
| UPS | Uninterruptible Power Supply |
| VoIP | Voice over Internet Protocol |
| VPN |
Virtual Private Network Portal used for secure remote access. |
| WAN | Wide Area Network |
| WLAN | Wireless Local Area Network |
| XFER | Transfer |
| XFRLIST | Transfer List |
Transit Terms
Operational Terms
Operational Terms refer to terminology that can vary slightly in meaning across the industry. The definitions below are how Avail defines these terms. These definitions are generic and subject to variations in interpretation in some situations.
| Operational Terms | Definition |
|---|---|
| Accessible Vehicle | A revenue vehicle that does not restrict access, is usable, and provides allocated space and/or priority seating for individuals who use wheelchairs. |
| Active Vehicle | A vehicle in the year-end fleet that is available to operate in revenue service, including spares and vehicles temporarily out of service for routine maintenance and minor repairs. |
| Block |
The work assigned to an individual vehicle, which consists of one or more patterns of one or more routes. A block will be assigned to only one vehicle, but a vehicle may be assigned to several blocks. |
| Deadheads |
When the vehicle is being driven without providing passenger service. Deadheading from the garage to the start of a route or deadheading between routes are defined as individual trips and are stored in a special route assigned a unique ID number (such as 99 or 999). |
| Near Real Time | A time interval that is as close to real-time (immediate) as allowed by technology. As an example, when the MDC issues a ‘vehicle location report’, it passes to the radio/cellular modem, the wireless network gateway, and the AVL system. The information must then wait for the next dispatcher screen refresh, therefore anywhere from 1 second to a couple of minutes may pass before a dispatcher will see the updated location information. |
| Non-Ridership | Objects that require space or driver time but is not charged a fare. (E.g. bicycles or wheelchairs.) |
| Passenger Miles | The cumulative sum of the distances ridden by each passenger. |
| Pattern |
A particular collection of stops and run times between stops within a route, which defines an instance of a route. A route will have one or more patterns. |
| Route |
The superset of stops from which patterns are made for specific executions of the route. A Transit Authority will have one or more routes. |
| Run | Run is a driver’s workload, consisting of a list of trips by a given driver.
|
| Service Level |
Defines the days of the year when the same service is provided to the riding public. Common service levels include Weekdays, Saturday, Sunday, Holiday, and No Service. A Transit Authority will have one or more service levels. |
| Stop | Specific locations where the vehicle takes on or discharges passengers.
|
| Trigger box | GPS coordinate set that defines two corners of a geographic square or rectangle that triggers events in the MDC |
| Trip |
A trip is a specific segment (pattern) of a route with a specific start time. NOTE: A trip may be either deadhead travel or revenue service. A trip is defined by route and start time and can be done by multiple vehicles. There is one trip per vehicle, but there can be multiple vehicles on the trip. |
| Unlinked Passenger Trips | The number of passengers who board public transportation vehicles. Passengers are counted each time they board vehicles no matter how many vehicles they use to travel from their origin to their destination. |
| Vehicle Hours | The hours a vehicle travels from the time it pulls out from its garage to go into revenue service to the time it pulls in from revenue service. It is often called platform time. For conventional scheduled services, it includes revenue time and deadhead time. |
| Vehicle Miles | The miles a vehicle travels from the time it pulls out from its garage to go into revenue service to the time it pulls in from revenue service. It is often called platform miles. For conventional scheduled services, it includes revenue time and deadhead time. |
| Vehicle Revenue Hours | The hours traveled when the vehicle is in revenue service (i.e., the time when a vehicle is available to the general public and there is an expectation of carrying passengers). These passengers either pay fares directly, are subsidized by public policy, or provide payment through some contractual arrangement. Vehicles operated in fare-free service are considered in revenue service. Revenue service excludes school bus service and charter service. For conventionally scheduled services, vehicle revenue hours are comprised of 2 elements: running time and layover/recovery time. |
| Vehicle Revenue Miles | The miles traveled when the vehicle is in revenue service (i.e., the time when a vehicle is available to the general public and there is an expectation of carrying passengers). These passengers either pay fares directly, are subsidized by public policy, or provide payment through some contractual arrangement. Vehicles operated in fare-free service are still considered in revenue service. Revenue service excludes school bus service and charter service. For conventionally scheduled services, vehicle revenue miles are comprised of running miles only. |
| View | A view within the AVL system refers to a specific center point on the map with a specific amount of zoom. |
General Terms
General Terms have specific industry standard meanings. These terms are often defined by some governing body such as the FTA.
| General Terms | Definitions |
|---|---|
| Average Trip Length | The average distance ridden for an unlinked passenger trip by time period (weekday, Saturday, Sunday) computed as passenger miles divided by unlinked passenger trips. |
| Bus rapid transit (BRT) | A type of limited-stop service developed in the 1990s that relies on technology to help speed up the service. It can operate on exclusive transit-ways, high-occupancy-vehicle lanes, expressways, or ordinary streets. A BRT line combines intelligent transportation systems technology, priority for transit, rapid and convenient fare collection, and integration with land use policy in order to substantially upgrade bus system performance. |
| Demand Response / Paratransit / Dial-a-ride |
Service comprised of passenger cars, vans, or small buses operating in response to calls from passengers or their agents to the transit operator, who then dispatches a vehicle to pick up the passengers and transport them to their destinations. A demand response operation is characterized by the following: (a) The vehicles do not operate over a fixed route or on a fixed schedule except, perhaps, on a temporary basis to satisfy a special need; and (b) typically, the vehicle may be dispatched to pick up several passengers at different pick-up points before taking them to their respective destinations and may even be interrupted in route to these destinations to pick up other passengers. The following types of operations fall under the above definitions provided they are not on a scheduled fixed route basis: many origins-many destinations, many origins-one destination, one origin-many destinations, and one origin-one destination. Complementary paratransit service is required by law for those persons with disabilities and others not able to use fixed-route service. Generally, it must operate in the same areas and during the same hours. The fare is limited to twice the fixed-route fare. Service may be the fixed-route bus agency or by a completely separate agency. General demand response service is not required by law and is not subject to the restrictions imposed on complementary paratransit service. The transit agency may limit the service to certain people or it may be available to anyone. Some such services operate during late-night and weekend hours in place of fixed-route services. User-side subsidy service is a transportation arrangement where the rider's cost of transportation is partially subsidized by the transit agency. The user is the rider who pays a reduced fare. A typical user-side subsidy program is operated through taxicab operators or a brokerage system which may charge a per-ride fee for handling the rider's transportation arrangements. |
| Express service | Faster / longer trips, especially in major metropolitan areas during heavily-patronized peak commuting hours, by operating long distances without stopping. Examples include park-and-ride routes between suburban parking lots and the central business district that operate on freeways, and express buses on major streets that operate local service on the outlying portions of a route until a certain point and then operate non-stop to the central business district. |
| Fixed-route | Service provided on a repetitive, fixed-schedule basis along a specific route with vehicles stopping to pick up and deliver passengers to specific locations; each fixed-route trip serves the same origins and destinations, unlike demand response. Includes route deviation service, where revenue vehicles deviate from fixed routes on a discretionary basis. |
| Intermodal / Multimodal | Issues or activities which involve or affect more than one mode of transportation, including transportation connections, choices, cooperation, and coordination of various modes. |
| Limited-stop service | A hybrid between local and express service, where the stops may be several blocks to a mile or more apart to speed up the trip. |
| Local service | Where vehicles may stop every block or two along a route several miles long, is by far the most common type of bus service. Trolleybuses, unless bypass overhead wiring is available, cannot pass the trolleybus in front of them, and thus generally operate in local service only. |
| Mode |
The system for carrying transit passengers described by specific right-of-way, technology, and operational features. Transit data are generally collected by mode. (Bus / Light Rail / Heavy Rail/ …) |
| Non-fixed-route | Service that is not provided on a repetitive, fixed-schedule basis along a specific route to specific locations. Demand response is the only non-fixed-route mode. |
| Passenger Miles | The total of the distances ridden by each passenger. This is an approximation due to the limited accuracy of the APC devices. |
| Public transportation | (public transit, transit, mass transit, mass transportation) is transportation by a conveyance that provides regular and continuing general or special transportation to the public, but not including school buses, charter or sightseeing service. |
| Shuttle Service | When limited to a small geographic area or to short-distance trips, local service is also called circulator, feeder, neighborhood, or trolley service. Such routes, which often have a lower fare than regular local service, may operate in a loop and connect, often at a transfer center or rail station, to major routes for travel to more far-flung destinations. Examples are office park circulators, historic district routes, transit mall shuttles, rail feeder routes, and university campus loops. |
| Transit Agency or Transit System | An entity (public or private) responsible for administering and managing transit activities and services. Transit agencies can directly operate transit service or contract out for all or part of the total transit service provided. When responsibility is with a public entity, it is a public transit agency. When more than one mode of service is operated, it is a multimode transit agency. |
| Unlinked Passenger Trips | The number of passengers who board public transportation vehicles. Passengers are counted each time they board vehicles no matter how many vehicles they use to travel from their origin to their destination. Therefore, the same person is counted multiple times if they use multiple vehicles to reach their destination. |