What is AADT? (Annual Average Daily Traffic) - The annualized average 24-hour volume of vehicles at any given point or section of highway. This is normally calculated by determining the volume of vehicles during a given period, then dividing that number by the number of days in that period. (Also known as a "Traffic Count.")

What is a train CONSIST? - This is a document showing the number of loaded or empty cars, weight in tons, and length in feet of a specific train. A locomotive consist shows the identifying number and location of each locomotive within that consist for a specific train. The term may also refer to the make-up of the train itself.

What is the ENS? (Emergency Notification System) - This is a sign, posted at or near a crossing, that lists a telephone number along with a US DOT number. The ENS is used to notify the railroad of an emergency or warning device malfunction.

What is GCCI? (Grade Crossing Collision Investigation) - This is a class to teach law enforcement officers about rail operations, showing them how to safely investigate rail-related incidents and collisions.

What is a GRADE SEPARATION? - This involves the crossing of a roadway and a railroad at different elevations, such as a highway bridge crossing over railroad tracks or vice versa.

What does the term MILEPOST NUMBER mean? - This is the railroad's system, measured in miles from a given point along the tracks, for identifying a location on those tracks.

What is an OFFICER ON THE TRAIN event? - This is an Operation Lifesaver safety program bringing local, county and state law enforcement officers into the locomotive cab. It allows officers to observe highway-rail grade crossing problems first-hand and to assist enforcement of motor vehicle laws at railroad crossings.

What is OL? (OPERATION LIFESAVER) - We are a national, non-profit public education and awareness organization dedicated to reducing collisions, deaths and injuries at highway-rail grade crossings and along railroad rights-of-way.

What is a PARALLEL TRACK SIGN? - This is a yellow, diamond-shaped warning sign found on roads running parallel to railroad tracks indicating the road ahead will cross those tracks. It also warns drivers making a turn that there is a highway-rail grade crossing immediately after the turn.

What is a PASSIVE CROSSING? - This is a crossing without active warning devices that contains passive warning devices such as a crossbuck, yield or stop sign.

What is a RAILROAD RIGHT-OF-WAY? - This term pertains to the private land, property or interest therein extending a set distance on either side of the railroad tracks.

What is RSER? (Rail Safety for Emergency Responders GCCI) - This is a class for emergency response personnel covering the special techniques involved with conducting vehicle/train collision investigations and the related hazards. This class may be sponsored by Operation Lifesaver, a railroad company, and/or national and local police agencies. (See "What is GCCI?")

What does the term SECTION 130 mean? - This refers to the FEDERAL-AID CROSSING SAFETY IMPROVEMENT PROGRAM, Section 130, Title 23 U.S.C., Highway-Rail. This program requires each state to conduct and systematically maintain a survey of all public crossings, identifying those needing attention, and providing funds for highway-rail grade crossing safety improvements. The improvements could be for separation, relocation, warning signs and devices, and surfaces. Section 130 also requires that each state establish and implement a schedule of projects for this purpose, minimally requiring it to provide signs for all highway-rail grade crossings.

What is TRACK CIRCUIT? - This refers to an electrical circuit using rails as part of the circuit. Track circuits are used to detect trains and activate warning signals.

What is a TRESPASSER? - A trespasser is anyone on railroad property whose presence if prohibited, forbidden or unlawful. An individual on a highway-rail grade crossing is not to be classified as a trespasser unless the crossing is equipped with gates - or other similar barriers - that were closed when they went on the crossing, or unless they tried to pass over, under or between cars or locomotives occupying the crossing.

What is an emergency notification system sign?

An Emergency Notification System (ENS) sign, posted at or near a highway-rail grade crossing, lists a telephone number along with the crossing's US DOT number and is used to notify the railroad of an emergency or warning device malfunction.