| Terms | Definitions |
|---|
| SMI | Significant Marine Incident indicator. ( Marine Casualty and Pollution Database ) |
| SO2 | Sulfur Dioxide ( National Air Quality Data (AIRS) ) |
| SO2 Emissions | Sulfur Dioxide, one of the six criteria air pollutants that EPA has set a national air quality standard for. belongs to the family of sulfur oxide gases (SOx). These gases dissolve easily in water. Sulfur is prevalent in all raw materials, including crude oil, coal, and ore that contains common metals like aluminum, copper, zinc, lead, and iron. Over 65% of SO2 released to the air, or more than 13 million tons per year, comes from electric utilities, especially those that burn coal. ( National Emissions Trends ) |
| STCC Code | Standard Transportation Commodity Classification ( Pipeline Safety Statistics ) |
| STRAHNET | Strategic Highway Corridor Network; The STRAHNET includes highways which are important to the United States strategic defense policy and which provide defense access, continuity, and emergency capabilities for the movement of personnel, materials, and equipment in both peacetime and war time. ( Highway Perfomance Monitoring System ) |
| SWATH | Small-Waterplane-Area Twin Hull ship. An experimental hull configuration similar to the two-hulled catamaran, but with submerged hulls connected to the above-water deck by thin struts. This allows for a wide deck and reduced drag, but is not suitable for heavy loads. ( National Ferry Database ) |
| Scheduled Departure Time | The scheduled time that an aircraft should lift off from the origin airport. ( Airline On-Time Performance Data ) |
| Scheduled Departures | Takeoffs scheduled at an airport, as set forth in published schedules. (same as Departures Scheduled) ( Small Air Carrier Statistics ) |
| Scheduled Service | Transport service operated persuant to published flight schedules, including extra sections and related nonrevenue flights. ( Small Air Carrier Statistics, Air Carrier Financial Reports (Form 41 Financial Data) ) |
| Scheduled Time Of Arrival | The scheduled time that an aircraft should cross a certain point (landing or metering fix). ( Airline On-Time Performance Data ) |
| Scheduled Vehicle Revenue Miles | The vehicle revenue miles computed from the scheduled service. It includes only the scheduled vehicle revenue miles from the whole trip. It excludes deadhead, service interruptions and special additional services. ( National Transit Database ) |
| School Bus-Related Crash | Any crash in which a vehicle, regardless of body design, used as a school bus is directly or indirectly involved, such as a crash involving school children alighting from a vehicle. ( Fatality Analysis Reporting System, General Estimates System (NASS/GES) ) |
| Seasonal Service | A service provided during a limited period each year (e.g., a ferry that runs all year except during the winter). ( National Ferry Database ) |
| Seat Mile | The aircraft miles flown in each inter-airport segment multiplied by the number of seats available on that segment for revenue passenger use. ( Small Air Carrier Statistics, Air Carrier Summary Data ) |
| Seating Position | The location of the occupants in the vehicle. More than one can be assigned the same seat position; however, this is allowed only when a person is sitting on someone's lap. ( Fatality Analysis Reporting System ) |
| Seats Available | Installed seats in an aircraft (including seats in lounges) exclusive of any seats not offered for sale to the public by the carrier; provided that in no instance shall any seat sold be excluded from the count of available seats. ( Air Carrier Statistics ) |
| Seaworthiness | Being fit or safe for a sea voyage. ( Marine Casualty and Pollution Database ) |
| Segment | A pair of points served or scheduled to be served by a single stage of at least one flight at any given time. ( Air Carrier Statistics ) |
| Segmented Trip | A trip that includes at least one transfer. ( Nationwide Personal Transportation Survey ) |
| Self Propelled | A vessel having its own means of propulsion, whether mechanical, natural, or other. ( Marine Casualty and Pollution Database ) |
| Service Area | A measure of access to transit service in terms of population served and area coverage (square miles). The reporting transit agency determines the service area boundaries and population for most transit services using the definitions contained in the Americans with Disabilities Act (ADA). ( National Transit Database ) |
| Shallow Draft Vessels | Barges, ships, or ferries operating primarily on rivers and canals; in harbors, the Great Lakes, the Saint Lawrence Seaway; the Intracoastal Waterway, the Inside Passage to Alaska, major bays and inlets; or in the ocean close to the shoreline. ( Commodity Flow Survey ) |
| Shipment | An individual movement of commodities from an establishment to a customer or to another location of the originating company (including a warehouse, distribution center, retail or wholesale outlet). A shipment uses one or more modes of transportation including parcel delivery, U.S. Postal Service, courier, private truck, for-hire truck, rail, water, pipeline, air, and other modes. ( Commodity Flow Survey ) |
| Sideswipe | A collision in which the sides of both vehicles sustain minimal engagements. ( Fatality Analysis Reporting System ) |
| Single-Unit Truck | A medium or heavy truck in which the engine, cab, drive train, and cargo area are all on one chassis. ( Fatality Analysis Reporting System ) |
| Sinking | Losing enough buoyancy to settle below the surface of the water. ( Marine Casualty and Pollution Database ) |
| Sky Condition Ceiling | The height above the earth's surface of the lowest layer of clouds or obscuring phenomena that is reported as broken, overcast, or obscuration, and not classified as thin or partial. ( Aviation Accidents Database and Synopses ) |
| Sleeper | An optional truck segment, located behind the truck cab and in front of the cargo storage area, which contains sleeping quarters and other ammenities. ( Trucks Involved Fatal Accidents ) |
| Small Certificated Air Carrier | An air carrier holding a certificate issued under section 401 of the Federal Aviation Act of 1958, as amended, that operates aircraft designed to have a maximum seating capacity of 60 seats or fewer or a maximum payload of 18,000 pounds or less. ( Small Air Carrier Statistics ) |
| South Atlantic Division | Delaware, Maryland, District of Columbia, Virginia, West Virginia, North Carolina, South Carolina, Georgia, Florida ( American Travel Survey ) |
| Special Use Vehicle | Indicates if the vehicle has a special use (e.g., taxi, military, police, ambulance, fire) and was being used for that purpose at the time of the incident. ( General Estimates System (NASS/GES) ) |
| Standard Classification Of Transported Goods | A commodity coding system developed jointly by agencies of the United States and Canadian governments based on the Harmonized System to address statistical needs in regard to products transported. (acronym SCTG) ( Commodity Flow Survey ) |
| Standard Industrial Classification (SIC) System | A system used by the Federal government to group similar establishments into industries. The SIC Division Structure makes it possible to collect and calculate establishment data by broad industrial divisions, industrial groups, and specific industries. This data will be converted to a new industry classification system, the North American Industry Classification System (NAICS 2002) in 2003. ( State and Area Employment, Hours, and Earnings, Occupational Employment and Wage Estimates ) |
| A system used by the Federal government to groups similar establishments into industries. The SIC Division Structure makes it possible to collect and calculate establishment data by broad industrial divisions, industrial groups, and specific industries. BLS replaced the SIC system with the Standard Occupational Classification system in 1999. ( Occupational Employment and Wage Estimates ) |
| Standard Industrial Classification (SIC) system | A system used by the Federal government to group similar establishments into industries. The SIC Division Structure makes it possible to collect and calculate establishment data by broad industrial divisions, industrial groups, and specific industries. This data will be converted to a new industry classification system, the North American Industry Classification System (NAICS 2002) in 2003. ( State and Area Employment, Hours, and Earnings ) |
| Standard Occupational Classification System (SOC) | A system categorizing workers in one of about 770 detailed occupations. Together, these detailed occupations comprise 22 major occupational groups. The SOC system was created by the Office of Management and Budget and implemented by the Occupational Employment and Wage Estimates Survey in 1999. ( Occupational Employment and Wage Estimates ) |
| Starboard | Right side of ship when facing forward. ( Marine Casualty and Pollution Database ) |
| Stern | The end of a vessel, opposite of bow. ( Marine Casualty and Pollution Database ) |
| Straight Truck | Vehicle with the cargo body and tractor mounted on the same chassis. ( Trucks Involved Fatal Accidents ) |
| Stratum | A statistical subpopulation. ( General Estimates System (NASS/GES) ) |
| Structural Failure | A fracturing or giving way under stress of an essential physical element of the vessel ( Marine Casualty and Pollution Database ) |
| Substrat | Substratum; a statistical supopulation within a stratum. ( General Estimates System (NASS/GES) ) |
| Subway | An underground rail rapid transit system or the tunnel through which it runs. In local usage, sometimes used for the entire rail rapid transit system, even if it is not all beneath the ground surface ( National Transit Database ) |
Printable Version