Section 2: IntroductionAnchor: #i1007115
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 from the development served. The location and design of the driveway should take into account characteristics of the roadway, the abutting property and the potential users. In order to assure 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 drivewaysAnchor: #i1007120
- 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, which ever is greater. On sections with a drainage ditch, that part of a driveway from the edge of pavement to the right-of-way line.
- Delivery Driveway: A driveway for use by trucks (typically SU or larger design vehicles as defined by AASHTO) to deliver merchandise to a retail outlet and/or for use by service vehicles, such as for solid waste collection.
- 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.
- Driveway: Facility for entry and/or exit such as driveway, street, road, or highway that connects to the road under the jurisdiction of the department or municipality.
- Effective Turning Radius: The minimum radius appropriate for turning from the right-hand travel lane on the approach street to the appropriate lane of the receiving street. This radius is determined by the selection of a design vehicle appropriate for the streets being designed and the lane on the receiving street into which that design vehicle will turn. Desirably this should be at least 7.5 m [25 ft].
- Farm/Ranch Driveway: A 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.
- 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.
- Non-Residential/Commercial Driveway: Driveway having a traffic volume in excess of 20 vehicles per day and is not a Public Street/Road or a Residential Driveway.
- 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.
- One-way Driveway: A driveway designed for either an ingress/egress maneuver but not both.
- Public Driveway (Streets and Roads): A driveway providing ingress/egress from a roadway for which the right-of-way is deeded to and the roadway maintenance is performed by a village, town, city, county or municipal utility district.
- Radial Return or Flare Drop Curb: For Residential Driveways onto Collector and Local streets is Maximum of 10 feet and minimum of 3 feet. A radial return is always used where the posted or operating speed is greater than 45 mph and the design vehicle type exceeds 30 feet in length.
- Residential Driveway: A driveway serving a single-family residence or duplex and has less than 20 vehicles per day using the driveway.
- Service Driveway: A 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.
- Shared Driveway: A driveway shared by adjacent owners.
- 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.
- 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.
- Throat Width: The driveway width measured at the end of the return radii. Refer to Figure C-2.