Anchor: #i1000724
Validation is the process of using a previously calibrated model to predict traffic volumes and comparing predicted volumes with observed volumes for a year other than the calibration year.
Traffic Data and Analysis Manual
Anchor: #i1000738
Value engineering
Value Engineering is the systematic application of recognized techniques which identify the function of a product or service, establish a value for that function, and provide the necessary function reliability at the least overall cost.
Project Development Process Manual
Anchor: #i1000755
A vanpool is an organized ridesharing arrangement in which a number of people travel together on a regular basis in a van which may be company owned, individually owned, leased, or owned by a third party. Expenses are shared, and there is usually a regular volunteer driver.
Public Transportation Collection
Anchor: #i1000770
vane shear
A vane shear is a test used to determine the in-place shearing strength of fine grained soils which do not lend themselves to undisturbed sampling and triaxial testing.
Geotechnical Manual
Anchor: #i1000790
Vector is the system for digitally defining an image by mathematically calculating area boundaries and assigning a density value to the entire area. Illustrator and Freehand are vector-based drawing programs.
Communications Manual
Anchor: #i1000804
vegetation management
Vegetation management is the maintenance of highway right-of-way vegetation in an environmentally sensitive and uniform manner consistent with the special conditions presented by local climate, topography vegetation, and level of urbanization.
Maintenance Manual
vegetative protection
Vegetative protection is stabilization of erosive or sediment producing areas by covering the soil with a non-structural cover such as vegetation.
Anchor: #i1000825
Vehicle is a device in or by which a person or property is or may be transported or drawn on a public highway, other than a device used exclusively on stationary rails or tracks.
Transportation Code §502.001
Anchor: #i1000842
vehicle availability
Vehicle availability is the number of vehicles available to members of a household for travel purposes.
Traffic Data and Analysis Manual
Anchor: #i1000932
vehicle mile of travel
  1. Vehicle mile of travel is a unit to measure vehicle travel made by a private vehicle, such as an automobile, van, pickup truck, or motorcycle. Each mile traveled is counted as one vehicle mile regardless of the number of persons in the vehicle.
  2. Vehicle mile of travel is a measure of travel developed by multiplying a roadway section length (in miles) by the AADT.
  3. Traffic Data and Analysis Manual
Anchor: #i1005032
vehicle occupancy
Vehicle occupancy is the number of occupants in a vehicle during a vehicle trip including the driver.
Traffic Data and Analysis Manual
Anchor: #i1000959
vehicle onboard radar
Vehicle onboard radar is radar for collision avoidance.
Traffic Operations
Anchor: #i1000985
Vehicle Titles and Registration Division
The Vehicle Titles and Registration Division administers a statewide system of collecting fees for motor vehicle registration and certificates of title. In March of 1998, the Automobile Theft Prevention Authority Office (ATPA) became a section of VTR.
Inside TxDOT
Anchor: #i1001004
vehicles and motorized equipment
Vehicles and motorized equipment include over-the-road vehicles (trucks, sedans, vans) and road-building equipment (tractors, rollers, graders, drag lines, etc).
Occupational Safety Manual
vehicles per day
This is a measure of traffic volume and is used as the unit for Average Annual Daily Traffic.
Anchor: #i999538
vehicle trips
Vehicle trips are those trips made by individuals in a household driving a vehicle. These are generally reported as vehicle trips per household and/or vehicle trips per person. Vehicle trips per person are computed by summing all of the vehicle trips and dividing by the number of persons within a household. Vehicle trips per household is also referred to as the vehicle trip rate.
Traffic Data and Analysis Manual
Anchor: #i1001059
velocity head
symbol Hv
Velocity head defines water moving at a given velocity, the equivalent head through which it would have to fall by gravity to acquire the same velocity.
Hydraulics Manual
Anchor: #i1005577
  1. Vendor is an individual, partnership, corporation, or other business entity that is a party to a written contract for a purchase with the department.
  2. Purchasing Manual
  3. Vendor is defined as a supplier of project-produced material that is not the contractor.
  4. Quality Assurance Program Manual
Anchor: #i1001090
vendor identification number
Replaced by Texas Identification Number
Finance Division
Anchor: #i1001114
vendor name
Vendor name is the name of entity or person issued a vendor identification number or Texas Identification Number by the state comptroller.
Finance Division
Anchor: #i1001133
Vendor Payment System
Vendor Payment System is an information system managed by the Finance Division.
Finance Division
  1. Verification is to confirm, by either testing or comparison with a recognized standard, that specific requirements are being met.
  2. Verification is the comparison of the output of an instrument to standards in order to determine if its operation and/or accuracy meet the specifications.
  3. Manual of Testing Procedures
Anchor: #i1001169
verification sampling and testing
Verification sampling and testing is defined as sampling and testing performed to validate the quality of the product.
Quality Assurance Program Manual
Anchor: #i1001227
vertical alignment
Vertical alignment is a series of straight lines called grade lines connected by parabolic curves. This is the positioning of the roadway in the profile view.
Anchor: #i1001237
vertical curve
Vertical curve is a parabolic curve drawn tangent to two intersecting grade lines to provide a smooth transition from one grade to another.
Anchor: #i1001263
vicinity map
Vicinity map is a key inset of an overall view of a generalized area on the ROW map.
ROW Utility Manual
Anchor: #i1001278
A violation is any event that results in theft, loss, unauthorized use, unauthorized disclosure, unauthorized modification, unauthorized destruction, or degraded or denied services of information resources. A violation constitutes a breach of security and confidentiality.
Information Security Manual
Anchor: #i1001293
virgin material
Virgin material is material not previously used in construction. NOTE: This definition has been approved by the Specification Committee.
Manual of Testing Procedures
Anchor: #i1001307
virtual private network
A virtual private network (VPN) typically uses the Internet as the transport backbone to establish secure encrypted links with business partners and extend communications to regional and isolated offices. It significantly decreases the cost of communications for an increasingly mobile workforce because Internet access is generally local and much less expensive than dedicated remote access server connections. A VPN is a trusted network constructed so that remote users can communicate freely and safely between the remote networks through the untrusted, public network (Internet) by various means of encryption.
Information Security Manual
Anchor: #virus
A virus is a program that attaches itself to an executable file or vulnerable application and delivers a payload that ranges from annoying to extremely destructive. A file virus executes when an infected file is accessed. A macro virus infects the executable code embedded in Microsoft Office programs that allow users to generate macros.
Information Security Manual
Anchor: #i1001327
  1. Viscosity is the resistance of a material to flowing. A fluid which is “thick” and highly resistant to flowing has high viscosity. Material with the consistency of water is low viscosity, since it flows easily. Asphalt is graded by viscosity at 140º F.
  2. Viscosity is the degree to which a fluid resists flow under an applied force. The technical definition of viscosity is the shear divided by the shear rate. High viscosity fluids require a large force to induce flow (ex: asphalt). Low viscosity fluids require a small force to induce flow (ex: water). Viscosity may be used as a measure to determine the suitability of a material for an intended purpose.
  3. Manual of Testing Procedures
Anchor: #i1001343
Visible means capable of being seen, whether legible or not, without visual aid by a person with normal visual acuity.
Right of Way Manual
Anchor: #i1006287
vital records
Vital records are records that are necessary for TxDOT to do any of the following after a disaster: resume or continue operations; reaffirm authority and activity, including legal and financial positions; or protect the rights and interests of the department and its customers. Sometimes called; essential records.
Source: Information Security Manual
Vital records are records that are necessary for TxDOT resume or continue operations, reaffirm authority and activity, including legal and financial positions, and/or protect the rights and interests of the department and its customers following a disaster.
Source: 13 TAC §6.1(20); Records Management Manual
Anchor: #i1001371
voids, air pockets, in the mineral aggregate
  1. Voids in the mineral aggregate refers to all the space in the paving mixture not occupied by mineral aggregate particles. This includes both air and asphalt cement, but does not include any asphalt cement that has been absorbed into the aggregate particles themselves.
  2. Voids in the mineral aggregate refers to the volume of the intergranular void spaces between the aggregate particles of a compacted mixture that includes the air voids and volume of the asphalt not absorbed into the aggregates
  3. Manual of Testing Procedures
    National Center for Asphalt Technology
Anchor: #i1001407
V or E
Volt is the unit of electromotive force, electrical pressure, or difference of potential. Analogous to water pressure. One volt will cause one ampere of current to flow through a resistance of one ohm.
Highway Illumination Manual
Anchor: #i1001427
voltage drop
A result of current flowing through a resistance.

A current of 30 amperes flowing through 300 feet of No.8 conductor whose resistance loop is 0.3924 ohms will result in a voltage drop of 11.77 volts.
Anchor: #i1001462
volume to capacity ratio
The ratio of flow rate to capacity. The V/C may be the actual or projected rate of flow on a designated lane group during a peak 15-minute interval divided by the capacity of the lane group. The V/C ratio is a measure of capacity sufficiency, that is, whether or not the physical geometry provides sufficient capacity for the subject movement.
Anchor: #i1006682
A volumeter is test equipment used for determining in-place density of soils and base materials using Test Method TEX-114-E, Part I.
Anchor: #i1001483
A voucher is the accounting document used to make payment to an individual or entity.
Finance Division
Anchor: #i1001498
voucher requirements
Voucher requirements are the documents or documentation required to obtain reimbursement for travel expenses.
Travel Manual
Anchor: #vulnerability
In IT, a vulnerability causes systems prone to attach, more likely to have an impact on that system.
Information Security Manual
Anchor: #i1001523
vulnerability report
A vulnerability report is a computer related report containing information described in §2054.077(b), Government Code, as that section may be amended from time to time.
Information Security Manual
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