Section 2: Introduction
Anchor: #i1007115General Guidelines
Driveways provide the physical transition between the public highway and the abutting property. Driveways should be located and designed to minimize negative impacts on traffic operations while providing safe entry and exit to / from the abutting property. The location and design of the driveway should take into account characteristics of the roadway, the abutting property, and the potential users. To ensure that driveways provide for safe and efficient traffic movements, it is necessary to consider the driveway's critical dimensions and design features. This Appendix applies to new driveways, and modification of existing driveways.
Anchor: #i1007120Definitions
- Anchor: #HBEMTLDL
- 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; as defined by the Texas Administrative Code Title 43 Part 4 Chapter 11 Subchapter C §11.51(1). Anchor: #DFBELVAG
- Commercial Driveway: An entrance to, or exit from, any commercial, business, or similar type establishment. Anchor: #OQUPNQTA
- Divided Driveway: A driveway providing a raised or depressed median, between the ingress/egress sides of a driveway. Medians can be painted (fully traversable) when curbing is not allowed within the right-of-way, slightly raised curb (mountable) when U-turns are allowed or curbed (traversable) when U-turns are not allowed. Anchor: #XVXVFMAA
- Driveway Apron: On curb and gutter sections, that part of a driveway from the pavement to a selected point that is usually 6 inches in elevation above the edge of pavement (although it may vary by location or roadway) or to the right-of-way, whichever is greater. On sections with a drainage ditch, that part of a driveway from the edge of pavement to the right-of-way line. Anchor: #QFVKUETU
- Effective Turning Radius: The minimum radius appropriate for turning from the right-hand travel lane on the approach street or driveway to the appropriate lane of the receiving street or driveway. This radius is determined by the selection of a design vehicle appropriate for the streets or driveway being designed and the lane on the receiving street or driveway into which that design vehicle will turn. Urban roadways with limited distance from the road to the right of way line may use lesser radii that fit within state right of way. Anchor: #NFQBWNXR
- Farm/Ranch Driveway: A Private Driveway providing ingress/egress for vehicles and farm/ranch equipment associated with the operation of the farm/ranch. Such driveways may also serve the residence of persons living and working on the farm/ranch and the other associated buildings. Anchor: #QBLDHTVV
- Field Driveway: A limited-use Private Driveway providing occasional/infrequent ingress/egress for equipment used for the purpose of cultivating, planting and harvesting or maintenance of agricultural land, or by equipment used for ancillary mineral production. Anchor: #DETRAXSL
- Non-simultaneous Two-Way Driveway: A driveway intended to accommodate both entering and exiting traffic but not at the same time. For example, if an exiting vehicle is present in the driveway, the entering vehicle must wait until the exiting vehicle has cleared the driveway. Anchor: #GPOCBYPR
- One-way Driveway: A driveway designed for either an ingress or egress maneuver but not both. Anchor: #EVKDMCEI
- Private Driveway: An entrance to or exit from a residential dwelling, farm, or ranch for the exclusive use and benefit of the permittee; as defined by the Texas Administrative Code Title 43 Part 4 Chapter 11 Subchapter C §11.51(20). Anchor: #CSWMSEIQ
- Private Residential Driveway: A Private Driveway serving a residential dwelling with anticipated P design vehicle and less than 20 vehicles per day using the driveway. A Private Residential Driveway should be designed as a Commercial Driveway if the anticipated design vehicle is SU or larger, or more than 20 vehicles per day are anticipated to use the driveway. Refer to AASHTO's A Policy on Geometric Design of Highways and Streets for information on the various design vehicle designations. Anchor: #QSSRIRYA
- Public Driveway (Streets and Roads): An approach from a publicly maintained street, road, or highway; as defined by the Texas Administrative Code Title 43 Part 4 Chapter 11 Subchapter C §11.51(21). Refer to Chapter 2, Section 9 - Off-System Roadways Intersecting Department Projects for design requirements of Public Driveways. Anchor: #XXUAPIVN
- Radial Return or Flared Taper Return: The physical connection transition geometry between the driveway and the roadway. A Radial Return is a curved radius. On a curb and gutter section, a Flared Taper Return may be a drop-down curb (parallel to the roadway) or an angular return curb (chorded between roadway and driveway). The top of curb profile must be 10 percent or flatter. Anchor: #WIFEEPCQ
- Service Driveway: A Commercial, Public, or Private Driveway for occasional or infrequent use by vehicles or equipment to service an oil or gas well, electric substation, water well, water treatment plant, sewage lift station, waste water treatment plant, detention basin, water reservoir, emergency services, automated or remotely controlled pumping station, logging road, and other activities that may be identified by TxDOT. Anchor: #LELBVQXK
- Simultaneous Two-Way Driveway: A driveway designed with a combination of return radius and throat width that allows a selected design vehicle to enter at the same time that another selected design vehicle is exiting the driveway. Anchor: #GXHRDOVS
- Throat Length: The distance parallel to the centerline of a driveway to the first on-site location at which a driver can make a right turn or a left turn; measured on roadways with curb and gutter, from the face of the curb, and on roadways without a curb and gutter, from the edge of the shoulder. Refer to Figure C-2. Anchor: #WELYSYKE
- Throat Width: The driveway width measured at the end of the return radii. Refer to Figure C-2.