Section 2: Definitions

Acceleration Lane: A speed-change lane, including tapered areas, for the purpose of enabling a vehicle entering a roadway to increase its speed to a rate at which it can more safely merge with through traffic.

Access Connection: Facility for entry and/or exit such as a driveway, street, road, or highway that connects to a highway on the state highway system.

ADT: The average daily traffic volume. It represents the total two-way traffic on a roadway for some period less than a year, divided by the total number of days it represents, and includes both weekday and weekend traffic. Usually, ADT is adjusted for day of the week, seasonal variations, and/or vehicle classification.

Auxiliary Lane: A lane striped for use as an acceleration lane, or deceleration lane, right-turn lane, or left-turn lane, but not for through traffic use.

Connection Spacing: The distance between connections, which is measured along the edge of the traveled way from the closest edge of pavement of the first access connection to the closest edge of pavement of the second access connection.

Capacity: The number of vehicles that can traverse a point or section of a lane or roadway during a set time period under prevailing roadway, traffic, and control conditions.

Commercial Driveway: An entrance to, or exit from, any commercial, business, or similar type establishment

Corner Clearance: The distance along the edge of the traveled way from the closest edge of pavement of the intersecting roadway to the closest edge of pavement of the nearest access connection.

Corner Lot: A lot located at the intersection of two roadways that has frontage on each roadway.

Deceleration Lane: A speed-change lane, including tapered areas, for the purpose of enabling a vehicle that is exiting a roadway to leave the travel lanes and slow to a safe exit.

Department: The Texas Department of Transportation.

Directional Median Opening: An opening in a nontraversable median that accommodates specific movements, such as U-turn movements and/or left-turn movements from the highway, and physically restricts other movements.

Divided Highway: A highway with a median designed to separate traffic moving in opposite directions.

Drainage Structure: A circular pipe, elliptical pipe, arch pipe, box culvert, or other similar conduit installed for the purpose of draining the flow of surface water.

Field Driveway: A limited use driveway for the occasional/infrequent use by equipment used for the purpose of cultivating, planting, and harvesting or maintenance of agricultural land, or by equipment used for ancillary mineral production.

Frontage Road: A local street or road along an arterial highway allowing control of access and service to adjacent areas and property. A frontage road may also be referred to as a service road.

Full Median Opening: In a nontraversable median, an opening that allows all turning movements from the highway and the adjacent connection, as well as crossing movements.

Functional Area (Intersection): The area of an intersection necessary to provide all required storage lengths for separate turn lanes and for through traffic plus any maneuvering distance for separate turn lanes. The functional boundary of an intersection includes more than just the physical area of the intersection.

Intersection: Any at grade connection with a roadway, including two roads or a driveway and a road.

Level of Service (LOS): A measure of traffic flow and congestion. As defined in the Highway Capacity Manual, it is a qualitative measure describing operational conditions within a traffic stream, generally described in terms of such factors as speed and travel time, freedom to maneuver, traffic interruptions, comfort and convenience, and safety.

Limited Access Roadway: A roadway especially designed for through traffic and over, from, or to which owners or occupants of abutting land or other persons have no right or easement of access by reason of the fact that their property abuts such limited access facility or for any other reason. Interstate highways, parkways, and freeways are usually developed as limited-access facilities.

Local Access Management Plan: A plan or guideline in a formally adopted rule or ordinance that is related to the application of access management within the municipality's or eligible county's jurisdiction.

Local Access Road: A local public street or road, generally one parallel to a highway on the state highway system to which access for businesses or properties located between the highway and the local access road is provided as a substitute for access to the highway. A local access road may also be called a lateral road or reverse frontage road, depending on individual location and application.

Median: That portion of a divided highway separating the opposing traffic flows. A median may be traversable or nontraversable.

Median, Nontraversable: A physical barrier in a roadway or driveway that separates vehicular traffic traveling in opposite directions. Nontraversable medians include physical barriers (such as a concrete barrier, a raised concrete curb and/or island, and a grass or a swale median) that prohibit movement of traffic across the median.

Median Opening Spacing: The allowable spacing between openings in a non-traversable median to allow for crossing the opposing traffic lanes in order to access property or for crossing the median to travel in the opposite direction (U-turn). The distance is measured from centerline to centerline of the openings along the traveled way.

Median, Traversable: A median that by its design does not physically discourage vehicles from entering or crossing over it. This may include painted medians.

Permit: Authorization for entry to and/or exit from a state highway and adjacent real property, issued by the department under Transportation Code, Chapter 203.

Permittee: A real property owner, or the owner's authorized representative, who receives an access connection permit from the department to construct or modify an access connection from the owner's property to a highway on the state highway system.

Private Driveway: An entrance to or exit from a residential dwelling, farm, or ranch for the exclusive use and benefit of the permittee.

Public Driveway: An approach from a publicly maintained street, road, or highway.

Reverse Frontage Road: See "local access road".

Right of Way: A general term denoting land, property, or interest therein, usually in a strip, acquired for or devoted to transportation purposes.

Service Road: See "frontage road".

Shared Access: A single connection serving two or more adjoining lots or parcels.

Sight Distance: The distance visible to the driver of a passenger vehicle measured along the normal travel path of a roadway from a designated location and to a specified height above the roadway when the view is unobstructed by traffic.

Signal: A traffic control signal.

Stopping Sight Distance (SSD): The distance required by a driver of a vehicle, traveling at a given speed, to bring the vehicle to a stop after an object on the roadway becomes visible. It includes the distance traveled during driver perception-reaction time and the vehicle braking distance.

Storage Lane Length: The portion of an auxiliary lane required to store the number of vehicles expected to accumulate in the lane during an average peak period.

Temporary Access: Time-limited provision of direct access to a roadway. Such access must be closed when permit conditions for access removal are satisfied. Typically, such conditions relate to such time when adjacent properties develop in accordance with a joint access agreement or frontage road plan.

Traffic impact analysis: A traffic engineering study to the level of analysis determined by the Department that determines the potential current and future traffic impacts of a proposed traffic generator and is signed, sealed, and dated by an engineer licensed to practice in the state of Texas.

TxDOT: Texas Department of Transportation.

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