ADA
A federal civil rights law that prohibits discrimination against people with disabilities in areas such as employment, public services, transportation, public accommodations, and telecommunications.
APC
A system that tracks the number of passengers boarding and alighting at each stop, while also recording the time, location, and direction of travel. It typically uses infrared beams or cameras to count passengers. Stop locations are determined using data from Global Positioning Systems (GPS), signpost emitters, Geographic Information System (GIS) maps, odometer readings, and inertial navigation. The collected data is compiled and processed by an on-board computer or a central system to generate meaningful information.
BRT
Bus service designed to provide faster, higher-quality service than a conventional local bus route through features such as dedicated lanes, transit signal priority, branded stations, wider stop spacing, off-board fare collection, and higher-capacity vehicles.
CAD/AVL
Computer-Aided Dispatch and Automatic Vehicle Location. An integrated system combining real-time tracking of fleet vehicles with communication tools for dispatch operations.
Deadhead
The distance and time a transit vehicle travels without passengers, usually between the garage facility and the start of a route.
ETA
Estimated Time of Arrival. The predicted clock time or countdown duration when a transit vehicle is expected to reach a specific bus stop or station.
Farebox Recovery
The proportion of transit operating expenses covered by passenger fares, calculated by dividing total fare revenues by total operating costs.
GTFS
A standardized format for sharing public transit service details, including schedules, stops, and fares. This format helps transit agencies provide data that can be used by various software applications, such as trip planners, enabling users to access travel information and public transit services through their smartphones and similar devices.
Headway
The time interval between consecutive vehicles traveling in the same direction on a specific route, usually measured in minutes. This interval helps determine the frequency of service, with shorter headways indicating more frequent service. Headways can be based on demand, such as during peak periods, or set by policy, such as every 30 minutes. Headways can be regular, clock, or ragged, depending on scheduling consistency. In some contexts, “headway” may also refer to a gap or missed vehicle in service.
Interlining
The practice of using the same transit vehicle and/or operator to serve more than one route without returning to the garage. This method is often implemented at common terminals or where two or more routes share a common endpoint or are in close proximity. Interlining can improve operating efficiency and enhance passenger transfers. By minimizing vehicle requirements and reducing the need for transfers, interlining can enhance overall service performance. It is also referred to as through routes, interlock routes, or interlocking.
Jitney
A private vehicle carrying passengers over a regular, semi-fixed route on a flexible schedule, common in developing markets or transit deserts.
Kneeling Bus
A bus equipped with air suspension systems that temporarily lower the front curb-side corner to reduce boarding height steps for passengers.
Layover
The scheduled interval at a transit terminal between the arrival of a vehicle at the end of a route and its departure for the next trip. This period, also known as recovery time, allows for delays, operator breaks, and preparation for the return journey. It encompasses both the time allotted for these activities and the specific location designated for the operator to stop between trips to adhere to the schedule. This ensures that vehicles remain on track and provides a buffer for any delays experienced during the previous trip.
MaaS
Mobility as a Service. The integration of various forms of transport services (including public transit, micro-mobility, and ride-hailing) into a single unified on-demand interface.
NTD
National Transit Database. The primary agency record repository in the United States collecting performance data, financial statistics, and safety variables from public transit providers.
OTP
On-Time Performance. A key performance indicator measuring actual trip arrival/departure times relative to public schedule matrices (typically -1 to +5 minutes variance).
Paratransit
Specialized transport services for people with disabilities or limited mobility, operating on demand rather than fixed route schedules, as mandated by the ADA.
Ridership
The total passenger volume carried by a transit system during a specific billing or scheduling interval, counted as either boardings or linked trips.
Shuttle
A transit vehicle operating on fixed loops or linear routes connecting high-demand transfer hubs, corporate offices, or educational campuses.
TSP
Transit Signal Priority. Systems that detect approaching public transit vehicles and adjust traffic signal timing sequences (green extension/red truncation) to minimize delay variables.
UPT
Unlinked Passenger Trips. Count of passenger boardings. Each boarding is calculated as one UPT, regardless of transfers between modes or separate routes.
Vehicle Revenue Hours
The total hours that vehicles are scheduled to or actually travel while in revenue service. This includes layover or recovery time. It excludes deadhead time, operator training, vehicle maintenance testing, and other non-revenue uses of vehicles.
Xpress Bus
An express public transit service with fewer stops and faster travel times, running between suburban communities and central commercial business districts.
Yard
A facility where revenue vehicles are stored, maintained, and serviced, and where operators report for their assignments. Vehicles are dispatched and recovered here for scheduled service. This facility is also known as a barn, base, depot, district, division, station, or yard.