| Terms | Definitions |
|---|
| T-100 | A section of Form 41, which includes non-stop segment and on-flight market data. Air carriers are required to periodically file Form 41 with the Bureau of Transportation Statistics. ( Aviation Support Tables ) |
| Tank Farm | An installation used by gathering and trunk pipeline companies, crude oil producers, and terminal operators (except refineries) to store crude oil. ( Pipeline Safety Statistics ) |
| Tanker | A vessel designed to haul liquid bulk cargo. ( Foreign Traffic Vessel Entrances and Clearances ) |
| Taxi-In Time | The time elapsed between wheels down and arrival at the destination airport gate. ( Airline On-Time Performance Data ) |
| Taxi-Out Time | The time elapsed between departure from the origin airport gate and wheels off. ( Airline On-Time Performance Data ) |
| Through Lane | Roadway lanes that are not turning lanes, exit, or entrance ramps. ( Highway Perfomance Monitoring System ) |
| Ticket | In 1994, the Coast Guard began issuing notice of violations (tickets) to parties known to have discharged 100 gallons or less of oil into the navigable waters of the United States. The notice of violation program accounts for 50 percent of the number of marine pollution incidents in the U.S.--but only a fraction of the quantity of oil discharged into U.S. waters. Ticket cases account for three percent of the volume of oil spilled in U.S. waters. Oil spills over 100 gallons or other substances discharged into the navigable waters of the U.S. are located in the MINMod database. ( Marine Casualty and Pollution Database ) |
| Timetable Station | A scheduled stop for a train. ( Railroad Accident/Incident Reporting System ) |
| Ton Mile | One ton (2,000 pounds) transported one statue mile. Ton-miles are computed by multiplying the aircraft miles flown on each inter-airport segment by the number of tons carried on that segment. ( Small Air Carrier Statistics, Air Carrier Summary Data ) |
| The weight times the mileage for a shipment. The respondents reported shipment weight in pounds, and mileage was calculated as the distance between the shipment origin and destination ZIP Codes. For shipments by truck, rail, or shallow draft vessels, the mileage excludes international segments. Aggregated pound-miles were converted to ton-miles (based on short tons). The ton-miles data are displayed in millions. ( Commodity Flow Survey ) |
| Tons Shipped | The total weight of an entire shipment. Respondents reported the weight in pounds. Aggregated pounds were converted to short-tons (2,000 pounds). The tons data are displayed in thousands. ( Commodity Flow Survey ) |
| Total Itinerary Yield | Itinerary fare per itinerary miles flown. The itinerary includes all segements of a journey from origin to destination. ( Airline Origin and Destination Survey (DB1B) ) |
| Total Modal Activity | The overall activity (e.g., ton-miles) of a specific mode of transportation, whether used in a single-mode shipment, or as part of a multiple-mode shipment. For example, the total modal activity for private truck is the total ton-miles carried by private truck in single-mode shipments, combined with the total ton-miles carried by private truck in all multiple-mode shipments that include private truck (private truck and for-hire truck, private truck and rail, private truck and air, etc.) ( Commodity Flow Survey ) |
| Total Reportable Damage | Includes labor costs and all other costs to repair or replace in kind damaged on-track equipment, signals, track, track structures or roadbed. Reportable damage does not include the cost of clearing a wreck; however, additional damage to the above listed items caused while clearing the wreck is to be included in your damage estimate. ( Railroad Accident/Incident Reporting System ) |
| Towed Trailing Unit | Any device attached to a motor vehicle by a hitch, including tractor trailer combinations, boat hitched on to motor vehicle, etc. This does not include towed vehicles, such as a tow truck towing a car. ( Trucks Involved Fatal Accidents ) |
| Toxicology | The study of the nature and mechanism of toxic effects of substances on living organisms and other biologic systems. ( Aviation Accidents Database and Synopses ) |
| Track | The actual flight path of an aircraft over the surface of the earth. ( Airline Origin and Destination Survey (DB1B) ) |
| Track Class | Track classes are minimum safety requirements for rail track, as established by the Federal government. The standards are more stringent as train speeds increase. For example, standards are higher for class 9 track (speeds up to 200 mph) than for class 1 track (10 mph for passenger trains, 15 mph for freight trains). ( Railroad Accident/Incident Reporting System ) |
| Track Type | Includes the following types of tracks: Main track: A track, other than an auxiliary track, extending through yards or between stations, upon which trains are operated by time table or train order or both, or the use of which is governed by a signal system; Industry track: A switching track, or series of tracks, serving the needs of a commercial industry other than a railroad; Siding: A track auxiliary to the main track used for meeting or passing trains; Yard track: A system of tracks within defined limits used for the making up or breaking up of trains, for the storing of cars, and for other purposes over which movements not authorized by time table or by train order may be made, subject to prescribed signals, rules or other special instructions. Sidings and industry tracks are not included, nor is main line within yard limits. ( Railroad Accident/Incident Reporting System ) |
| Traffic Accident | An accident that involved a motor vehicle that occurred on a public highway or road in the United States and that resulted in property damage or personal injury. Does not include accidents that happened in a parking lot, in a driveway, on a private road, or in a foreign country. ( Nationwide Personal Transportation Survey ) |
| Traffic Analysis Zone (TAZ) | Level of geographic detail used in most transportation planning applications to summarize socio-economic characteristics and travel data. TAZs vary in size depending on density and homogeneity of land uses, and are defined by local agencies. ( Census Transportation Planning Package ) |
| Traffic Control Device | A sign, signal, marking, or other device placed on or adjacent to a street or highway, by authority of a public body or official that has jurisdiction, to regulate, warn, or guide traffic. ( General Estimates System (NASS/GES), Trucks Involved Fatal Accidents ) |
| Traffic Flow Type | Denotes whether a trafficway accomodates undivided two-way traffic, divided two-way traffic (median and/or traffic barrier), or one-way traffic. ( Trucks Involved Fatal Accidents ) |
| Traffic Related Expenses | Expenses incurred due to traffic solicitor salaries, traffic commissions, passenger food expense, traffic liability insurance, advertising and other promotion and publicity expenses, and the fringe benefit expenses related to all salaries in this classification. ( Air Carrier Financial Reports (Form 41 Financial Data) ) |
| Trafficway | Any road, street, or highway open to the public as a matter of right or custom for moving persons or property from one place to another. ( Fatality Analysis Reporting System ) |
| Trailing Vehicle | Indicates if vehicle was pulling a trailer unit. A trailer unit can be a horse trailer, fifth wheel trailer, camper, boat, truck trailer, towed vehicle, or any other trailer. ( General Estimates System (NASS/GES) ) |
| Train Accident | Any collision, derailment, fire, explosion, act of God, or other event involving the operation of on-track equipment (standing or moving) that results in total damages to all railroads involved in the event that is greater than the current reporting threshold to railroad on-track equipment, signals, track, track structures, and roadbed. ( Railroad Accident/Incident Reporting System ) |
| Train Incident | An event involving the movement of on-track equipment that results in a reportable casualty but does not cause reportable damage above the threshold established for train accidents. ( Railroad Accident/Incident Reporting System ) |
| Train Mile | A unit of comparative measure equal to the movement of one train for a distance of one mile. ( Railroad Accident/Incident Reporting System ) |
| Train Revenue Hours | The hours that are comprised of running time and layover/recovery time. ( National Transit Database ) |
| Train Revenue Miles | The miles that are comprised of running time and layover/recovery time. ( National Transit Database ) |
| Transfer | To change vehicles or means of transportation while traveling between origin and destination. ( Nationwide Personal Transportation Survey ) |
| Transit Bus | A bus designed for frequent stop service with front and center doors, normally with a rear-mounted diesel engine, low-back seating, and without luggage storage compartments or rest room facilities. Includes motor bus and trolley coach. ( National Ferry Database ) |
| Transit System | An organization (public or private) providing local or regional multi-occupancy-vehicle passenger service. Organizations that provide service under contract to another agency are generally not counted as separate systems. ( National Transit Database ) |
| Transport-Related Expenses | All expense items applicable to the generation of transport-related revenues. ( Air Carrier Financial Reports (Form 41 Financial Data) ) |
| Transport-Related Revenues | Revenues from the transportation by air of all classes of traffic in scheduled and nonscheduled service. ( Air Carrier Financial Reports (Form 41 Financial Data) ) |
| Travel Day | A 24-hour period from 4:00 a.m. to 3:59 a.m. designated as the reference period for studying trips and travel by members of a sampled household. ( Nationwide Personal Transportation Survey ) |
| Travel Day Trip | A travel day trip is defined as any one-way travel from one address (place) to another by any means of transportation (e.g., private motor vehicle, public transportation, bicycle, or walking). When travel is to more than one destination, a separate trip exists each time one or both of the following criteria is satisfied: the travel time between two destinations exceeds 5 minutes, and/or the purpose for travel to one destination is different from the purpose for travel to another. The one exception is travel within a shopping center or mall. It is to be considered travel to one destination, regardless of the number of stores visited. ( Nationwide Personal Transportation Survey ) |
| Travel Party Size | Any of three groups depending on whether household and/or non-household members were on the trip. Travel Party is the total number of household and non-household members on the trip. Household Travel Party is the total number of household members on the trip. Non-Household Travel Party is the total number of non-household members on the trip. ( American Travel Survey ) |
| Travel Party Type | Any of eight categories describing the number of adults and children in the group. ( American Travel Survey ) |
| Travel Period | The 13 days immediately preceding the travel day and the designated travel day for a sampled household, for a total of 14 days. ( Nationwide Personal Transportation Survey ) |
| Travel Period Trip | A travel period trip is one-way to a destination, which is 75 miles-or-more from home with a return home trip during the 14-day travel period. Travel to the destination is counted as one trip and travel to return home is counted as another trip. For example, a person living in Denver flies to San Francisco, stays one week, and returns to Denver during the 14-day travel period. This would be counted as two travel period trips - one outgoing and one return. The only time a travel period trip would not have a return trip collected is when the respondent moves his/her residence. ( Nationwide Personal Transportation Survey ) |
| Trespass | To unlawfully enter land, a dwelling or other real property. ( National Transit Database ) |
| Trip | Each time a person goes to a place at least 100 miles away from home and returns. Respondents were asked to report trips of 75 miles or more as a means of reducing possible failure in reporting trips of 100 miles or more due to a misconception by the respondent of the actual miles traveled. Trips subsequently calculated to be less than 100 miles were excluded from the estimates. A household trip refers to a trip in which one or more members of a household traveled together. A person trip refers to a trip taken by an individual. For example, if three persons from the same household go together on a trip, the trip is counted as one household trip and three person trips. If persons goes alone on two trips, the trips are counted as two household trips and two person trips. ( American Travel Survey ) |
| Trip Chaining | A term used to refer to the phenomenon of making intermediate stops as part of a longer trip. For example, stopping at a convenience store or day care center as part of the trip from home to work. Chained trips were not reported in the 1990 Census data. ( Census Transportation Planning Package ) |
| Trip Purpose | The main reason that motivated the trip. For purposes of this survey, there are 11 trip reasons. For travel day trips, if there was more than one reason, and the reasons do not involve different destinations, then only the main reason is chosen. If there are two or more reasons, and they each involve different destinations, then each reason is classified as a separate trip. For travel period trips, if there was more than one reason, the primary reason was collected. The 11 trip reasons are defined as follows: To or from Work: Includes travel to a place where one reports for work. Does not include any other work-related travel. Work-related Business: Trips related to business activities except travel to the place of work; for example, a plumber drives to a wholesale dealer to purchase supplies for his business or a company executive travels from his office to another firm to attend a business meeting. Business, out- of-town trips, and professional conventions are also included. Shopping: Includes window-shopping and purchase of commodities such as groceries, furniture, clothing, etc. for use or consumption elsewhere. Doctor/Dentist: Trips made for medical, dental, or psychiatric treatment or other related professional services. Other family or personal business: Includes the purchase of services such as cleaning garments, servicing an automobile, haircuts, banking, legal services, etc. School/Church: Trips to school, college or university for class(es), to PTA meetings, seminars, etc., to church services or to participate in other religious activities. Social activities that take place at a church or school but cannot be classified as religious or educational are not included in this category. Vacation: Trips reported by the respondent as vacation. Visit friends or relatives: Trips made to visit friends or relatives. Pleasure driving: Driving trips made with no other purpose listed but to go for a drive with no destination in mind. Other social or recreational: Trips taken to enjoy some form of social activity involving friends or acquaintances. Includes trips for general entertainment or recreation (both as observer or as participant).Other social or recreational: Trips taken to enjoy some form of social activity involving friends or acquaintances. Includes trips for general entertainment or recreation (both as observer or as participant). Other: For trips that do not fit in any of the other categories. ( Nationwide Personal Transportation Survey ) |
| Trolleybus | A transit mode comprised of electric rubber tired passenger vehicles, manually steered and operating singly on city streets. Vehicles are propelled by a motor drawing current through overhead wires via trolleys, from a central power source not on board the vehicle. ( National Transit Database ) |
| Truck | Shipments using for-hire truck only, private truck only, or a combination of for-hire truck and private truck. ( Commodity Flow Survey ) |
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