TxDOT Glossary: R

radian: A radian is an arc of a circle equal in length to the radius. A radian is the angle at the center measured by the arc.; Survey Manual

radius: R; A radius is a line segment extending from the center of a circle to the curve.; Survey Manual

radius of gyration: A radius of gyration is the distance from the reference at which all of the area can be considered concentrated that still produces the same moment of inertia. Numerically, it is equal to the square root of the moment of inertia, divided by the area.

railroad crossing: RRX; A railroad crossing is a crossing of a highway and a railroad.

rainfall intensity: Rainfall intensity is a value expressing rainfall in terms of inches per hour used in hydraulic calculations. The term “one inch per hour of rainfall” equals approximately one cubic foot per second per acre.

ramp: A ramp is an interconnecting roadway or a traffic interchange on which vehicles may enter or leave a designated highway.

ramp, entrance: A ramp, entrance, is an interconnecting roadway for the transfer of traffic from a low-speed, local service facility to a higher-speed, through facility.

ramp, exit: A ramp, exit, is an interconnecting roadway for the transfer of traffic from a high-speed, through facility to a low-speed, local facility.

ramp, terminals: A ramp, terminals, is the nose of a ramp at its point of mergence or divergence with either a local street, frontage road, or traffic lane of the through highway.

ranch road: RR; Ranch road is only Ranch Road 1; considered part of the farm to market road system, so designated by the Texas Transportation Commission. Ranch road spur is also a roadway so designated by the Texas Transportation Commission, which is designated within the description of the ranch road.; Texas Reference Marker (TRM) System User's Manual

ranch to market road: RM; A ranch to market road is a roadway so designated by the Texas Transportation Commission. Ranch to market road spur is also a roadway so designated by the Texas Transportation Commission, which is designated within the description of the ranch to market road.; Texas Reference Marker (TRM) System User's Manual

raster: Raster is the system for digitally defining an image by dividing the image into a specified number of square areas and assigning one of 256 density values to each of these areas. Photoshop is a raster-based image-editing program.; Communications Manual

rated source: A rated source is a source with one or more aggregate products(s) meeting the AQMP, Aggregate Quality Monitoring Program, eligibility and acceptance criteria and rated statistically for quality by MAT.; Manual of Testing Procedures

rated source quality catalog: The rated source quality catalog is a catalog published biannually by MAT to update the rated source statistical values for the quality tests covered by the AQMP, Aggregate Quality Monitoring Program.; Manual of Testing Procedures; Inspection Guide

rational method of design drainage structure: A rational method of design drainage structure is a design method based on the principle that the maximum rate of run off from a given watershed for an assumed intensity of rainfall occurs when all parts of the area are contributing to the flow of discharge. Expressed as a formula this method becomes: Q = CIA.

raveling: Pavement Management Information System (PMIS) Users Manual; Maintenance Collection

readability: Readability is the smallest division or fraction of a division to which a visual output can be accurately read or estimated. For digital load indicators, this is the smallest incremental change for each range. NOTE: Some digital load indicators change readability without warning.; Some change from 0.01 to 0.02 and 0.05 g, others from 0.1 to 0.5 gas the weight increases.; Manual of Testing Procedures

read-only memory: ROM; Some computers and most microprocessors have some form of memory that represent either by the manufacturer or in some one-time process so that ROM only has one set of information and does not have the hardware to rewrite (and thus to erase) its contents.

real property: Real property is land, including improvements, structures, and appurtenances, but excluding movable machinery and equipment.; Public Transportation Collection

reappraisal: Reappraisal is a second or subsequent appraisal of property after the initial appraisal, updating the values for negotiation or eminent domain purposes, or due to a market change.; Right of Way Collection

Reasonable Accommodation Review Committee: RARC; The Reasonable Accommodation Review Committee is a committee to review accommodation requests that will cost more than $2,000. The RARC consists of representatives of the:; Human Resources Manual

rebuilt (re-life) equipment: Rebuilt (re-life) equipment is the complete refurbishment of a piece of equipment or the extensive refurbishment at an established interval to a major component, such as an aerial device.; Equipment Manual

receipts: Receipts are all cash deposits.; Finance Division

receiving agency: The receiving agency is the agency compensating the performing agency for services or resources.; Contract Management Manual

receiving district, division or office: The receiving district, division or office is the office responsible for preparing and managing the contract, including processing payments.; Contract Management Manual

receiving hopper: The receiving hopper is the front part of a paver, where hot mix is received from the haul truck.

receiving waters: Receiving waters are the waters into which runoff flows.

reciprocity: Reciprocity is a preference applied against a bidder whose home jurisdiction has preferences. Used for bid evaluation purposes only.; Purchasing Manual

reclassification: Reclassification is the process of reviewing the actual duties performed in a position and assigning the position to a state and business category consistent with the duties and job description. Reclassification is not to be interpreted as a change in duty assignment.; Human Resources Manual

recommended value: Recommended value is the value for a parcel recommended as just compensation by the reviewing appraiser after his/her review of the appraisal report.; Right of Way Collection

reconstruction (4R) project: Work proposed on the approximate alignment of an existing route that meets the geometric criteria for a new facility. Reconstruction includes new location projects or projects that provide substantial changes in the general geometric character of a highway, such as widening to provide additional through travel lanes, horizontal or vertical re-alignment, etc. Reconstruction work includes bridge replacement work.

record copy: The record copy of a document or collection of documents in a file is the “official” copy of a record subject to records retention requirements.; Records Management Manual

Record Of Decision: ROD; The final approval of an Environmental Impact Statement issued by the Federal Highway Administration.

record owner: A record owner is the owner of record in a particular political subdivision of the State.; Right of Way Manual

record series: A record series is a single specific type of record or file or a group of files that are similar in function and have similar retention requirements.; Records Management Manual

records retention schedule: A records retention schedule is a document describing records produced and maintained by TxDOT, including information on the minimum required retention, the medium of the record, its status as a confidential or vital record, and whether the record is subject to review by the State Archives before it may be destroyed.; 13 TAC §6.1(12); Records Management Manual

recreational road: RE; A recreational road is a roadway so designated by the Texas Transportation Commission. Recreational Road Spur is also a roadway so designated by the Texas Transportation Commission.; Texas Reference Marker (TRM) System User's Manual

recycled asphalt pavement: RAP; Recycled asphalt pavement is hot mix asphalt and any accompanying tack coat, seal coat or chip seal removed as millings or broken pavement pieces from a road during construction, reconstruction or repavement.; Materials and Supplies Management System Manual

reduction in force: RIF; Reduction in force is the involuntary separation from employment of employees whose positions have been eliminated for reasons not related to substandard performance or rule violations.; Human Resources Manual

redundant array of inexpensive disks: RAID; Redundant array of inexpensive disks is a type of data storage mechanism in which large numbers of small and inexpensive hard disks are utilized in combination to provide for data protection, redundancy and recoverability.

reference items: Reference items are standard or special specifications used to supplement other specifications. They are noted, mentioned, or referenced in the specification itself or in a plan or general note or by provision.; PS and E Preparation Manual

reference marker: A reference marker is the building block of the TRM Highway Data File and the link between the automated files and what is actually on the ground. Reference markers replace control-section-milepoint, milepost, link-node, or others as the sole source of location identification for highway-related on-system data.; Texas Reference Marker (TRM) System User's Manual

reference marker displacement: Reference marker displacement is the distance in miles from a posted reference marker on the signed highway route to a data attribute or feature.; Texas Reference Marker (TRM) System User's Manual

reference marker group: A reference marker group consists of the Reference Marker Number + Reference Marker Suffix + Signed Reference Marker Displacement.; Texas Reference Marker (TRM) System User's Manual

reference marker number: The reference marker number is the official number posted on the signed highway route. Markers are numbered from state line to state line and from westernmost or northernmost point of the Highway origin (south to north for interstate highway post numbering).; Texas Reference Marker (TRM) System User's Manual

reference marker sign: A reference marker sign is a symbol indicating the ascending (+) or descending (–) direction to a data attribute or feature from a posted reference marker.; Texas Reference Marker (TRM) System User's Manual

reference marker suffix: A reference marker suffix is the posted suffix character, if any, appended to the reference marker number on the signed highway route.; Texas Reference Marker (TRM) System User's Manual

reference temperature profile: Reference temperature profile is a graph generated by the match cure system representing time versus temperature (heat of hydration) of the in-situ concrete.; Manual of Testing Procedures

reference test report: Reference test reports are issued to any current project using item specific material on a QM program within the program guidelines.; Manual of Testing Procedures

reflector: A reflector is a polished aluminum device used to reflect light.; Highway Illumination Manual

reflector units: There are two types of reflector units. Type A reflector units have reflective sheeting applied to the substrate. Type B reflector units have center mounted acrylic plastic reflectors.; Manual of Testing Procedures

refractor: A refractor is a prismatic glass element used to refract light.; Highway Illumination Manual

refueling emissions: Refueling emissions are gasoline vapor emissions generated by the refueling of vehicles where the vapor in the vehicle fuel tank is displaced by the incoming liquid fuel and released into the atmosphere.; Traffic Data and Analysis Manual

regional automation center: RAC; A regional automation center is one of the TxDOT computer facilities at Austin (not the central system), Houston, Dallas, Ft. Worth, Odessa, and San Antonio in which large computers are in use by the department. These computers have extensive linkage between each other and the central system.

regional computing center: RCC; A regional computing center (RCC) provides district-to-center and center-to-Austin communications. Automated facilities are located at 6 host district offices (Houston, Dallas, Ft. Worth, Odessa, San Antonio, and Austin) that consist of IBM 4341 and VAX.

Regional Liaison Officer: RLO; A Regional Liaison Officer (RLO) is a member of the Governor’s Division of Emergency Management staff. The RLOs are stationed throughout the state. These field response personnel assist local officials in planning and carrying out emergency preparedness programs, teach a variety of emergency management courses, identify needs and advise local officials during incidents and disasters, and help coordinate state emergency resource support.; Maintenance Division

regional pooled-fund study: A regional pooled-fund study is a planning or RD&T study expected to solve problems of regional significance. The study is usually administered by an FHWA region office in cooperation with a lead state and/or MPO, that is funded by state and/or MPO contributions of FHWA planning and research funds, with or without matching funds.; Transportation Planning and Programming Collection

regionally significant project: A regionally significant project is a project (other than projects excluded by the cooperating parties from individual identification and grouped in the STIP/TIP) that is on a facility which serves regional transportation needs. Needs such as access to and from the area outside of the region, major activity centers in the region, major planned developments such as new retail malls, sports complexes, etc., or transportation terminals as well as most terminals themselves) and would normally be included in the modeling of a metropolitan area’s transportation network, e.g., all principal arterial highways and all fixed guideway transit facilities.; Transportation Planning and Programming Collection

registered professional land survey: RPLS; A registered professional land surveyor is a board certified professional qualified to provide value to the Texas Department of Transportation; Survey Manual

registration authority: RA; The registration authority keeps, monitors, and distributes certificates for the PKI process.; Information Security Manual

regular standby time: Regular standby time is standby time that is routinely scheduled for employees on a rotating basis.; Human Resources Manual

regular overtime: Regular overtime is time worked over eight hours in one day, on a paid holiday, or on weekends. All regular overtime worked is compensated with regular compensatory time at the rate of one hour earned for every hour worked. Regular compensatory time may be earned by non-exempt and exempt employees.; Human Resources Manual

regulated output ballast: A regulated output ballast is a form of electrical transformer that maintains the wattage of the lamp at a nearly constant value, though the line voltage may fluctuate as much as ±10 percent. Such ballasts or transformers may be integrally mounted within the luminaire or separately mounted in a ballast enclosure.; Highway Illumination Manual

regulated highway: A regulated highway is a highway on the interstate highway system or the primary highway system.; Right of Way Manual

regulatory signs: Regulatory signs are signs used to regulate the traffic movement or use of public highways and is law. A regulated sign is a sign permitted under the Transportation Code, Chapters 391 and 394 (outdoor advertising statutes).

rehabilitation (3R) project: Rehabilitation is work proposed to improve serviceability and extend the service life of existing highways and streets and to enhance safety. Work is usually accomplished within the existing right of way and does not include the addition of through travel lanes. Work may include the upgrading of geometric features such as roadway widening, minor horizontal re-alignment, and improving bridges to meet current standards for structural loading and to accommodate the approach roadway width.

reinforced concrete pavement: Reinforced concrete pavement is Portland concrete pavement in which steel is used to control the width of shrinkage and thermal cracking of the concrete. The steel adds strength to the concrete in tension.

reinforcement: Reinforcement is steel embedded in a rigid slab to resist tensile stresses and detrimental opening of cracks.; Pavement Design Manual

reinforcing steel: Reinforcing steel is steel bar, steel fabric, steel wire and seven-wire strand steel.; Manual of Testing Procedures

reinforcing steel producing mill: A reinforcing steel producing mill is a mill which performs the hot rolling of bar, cold drawing of wire, welding of welded wire fabric, or the stranding and heat-treatment of seven-wire strand.; Manual of Testing Procedures

relative importance factor: RIF; Relative importance factor is the numerical weight of each evaluation criterion as it relates to a particular contract.; Engineering Architectural and Surveying Services Manual

release of tension cylinders: Release of Tension Cylinders are cylinders used to determine when the concrete strength is adequate to apply the pretensioning force.; 700-I, Structural Test Procedures Manual

reliability: Reliability of a pavement design/performance process is the probability that a pavement section designed using the process will perform satisfactorily during the design period under the given traffic and environmental conditions.; Pavement Design Manual

relocation assistance: Reloc Asst; Relocation assistance is an advisory and/or financial aid to persons, businesses, farms and non-profit organizations displaced by a highway project to assist them in becoming re-established, at rents or prices within their financial means, in dwellings that are decent, safe and sanitary.; Right of Way Manual

relocation specialist: A relocation specialist is a person employed by the State to assist displaced persons with advisory or financial aid during their relocation.; Right of Way Manual

remainder: A remainder is that area of a parcel of land which remains in the possession of the property owner after the part to be acquired has been taken, either by purchase or condemnation by the State.; Right of Way Manual

remedies: Remedies are instructions provided (in accordance with the contract) to the performing entity for corrective action.; Contract Management Manual

remote access: Remote access is the use of a modem and communications software to connect to a computer network from a distant location via a telephone line or wireless connection; Information Security Manual

remote job entry: RJE; Remote job entry is used from the remote terminals in the computer systems in the department for users to input their data directly over data communication lines to computers. This avoids mailing the data or using telephones to get the data to the computer site. Output from the computer systems is also by remote job output.

remote job entry job control language: RJEJCL; Remote job entry job control language is a prompted, menu-driven programming function in regional remote operating system conversational online environment (ROSCOE) that assists the user in building job control language (JCL) and submitting jobs.; Design and Construction Information System Manual

remote location: Remote location is a specific location twenty or more miles from a MAT office.

Remote Operating System Conversational Online Environment: ROSCOE; Remote operating system conversational operating environment (ROSCOE) is an online text-editing and remote job entry system. It is actually designed as a text editor with a library to save and retrieve text. ROSCOE is not designed to be a word processor. ROSCOE interfaces with the computer operating system. This interface allows the user to submit batch jobs, to examine the output from those jobs, and to determine disposition (print, delete, very temporary retention, or resubmission after error correction).; Design and Construction Information System Manual

remote terminal access: Remote terminal access is access to a system by any terminal device which is not directly attached to it via a dedicated connection.

remote user: A remote user is one that is not located at the same place as is the computer system to which communications have been established. Remote communications for this type of user is usually established through dial-up telephone lines.

removable media: Removable media are materials that hold data in any form or that allow data to pass through them, including paper, transparencies, multipart forms, hard, floppy and optical disks, magnetic tape, wire, cable and fiber.; Information Security Manual

rented or public conveyance: Rented or public conveyance means a motor vehicle, train, or aircraft that an employee rents or pays for to use on a short-term basis while traveling on official state business.; Travel Manual

re-order point: ROP; A re-order point is when the inventory level is low enough to order stock.; Materials And Supplies Management System Manual

re-order quantity: ROQ; Re-order quantity is the quantity to order when the re-order point is reached.; Materials And Supplies Management System Manual

repeater: A repeater is a device that receives a digital signal on an electromagnetic or optical transmission medium and regenerates the signal along the next leg of the medium.; Information Security Manual

replacement credit: Replacement credit is an inventory notation in the public transportation management system (PTMS) that indicates TxDOT has awarded funds to replace a transit vehicle, regardless of whether a transit agency physically disposes of the vehicle.; Public Transportation Collection

request: A request is an order from a stock account or customer to another stock account.; Materials And Supplies Management System Manual

request for discussion: RFD; A request for discussion is a posting that proposes the creation of a new Usenet news group.; Information Technology and Services Manual

request for information: RFI; Request for information is a formal method of obtaining information to be used in a procurement.; Purchasing Manual

request for offer: RFO; Request for offer is a solicitation used with the catalog purchase procedure.; Purchasing Manual

request for proposal: RFP; Contract Management Manual; Purchasing Manual; Engineering Architectural and Surveying Services Manual; Public Transportation Collection

request for (price) quote: RFQ; Request for quote is a method of solicitation used for informal competitive bidding.; Purchasing Manual

requisition: A requisition is a request from a stock account to purchase an item.; Materials And Supplies Management System Manual

rescue service: Rescue service are the personnel designated to rescue employees from permit spaces.; Occupational Safety Manual

research: Research is a systematic, controlled inquiry, often involving analytical or experimental activities, which seeks to gain new knowledge and which may involve development of new or revised products. Research includes basic research, applied research, state-of-the-art or practice surveys and studies, development, and research field testing. Software program development which solely automates the use of existing technology, formulae, knowledge and methods is specifically excluded from the definition of research.; Research and Implementation Manual

Research and Technology Implementation Office: RTI; The TxDOT Research and Technology Implementation Office is charged with research and implementation program management.; Research and Implementation Manual

research management committee: RMC; A research management committee is one of five committees responsible for development of the research program.; Research and Implementation Manual

research oversight committee: ROC; The research oversight committee is comprised of the chairs of the RMCs, selected division and office directors, FHWA, plus a chair and vice-chair representing the TxDOT administration.; Research and Implementation Manual

resident bidder: A resident bidder is a business entity whose principal place of business is in Texas, including an entity whose ultimate parent company or majority owner has its principal place of business in Texas.; Letting Manual

resilient modulus: Resilient modulus is a measure of the modulus of elasticity of roadbed soil or other pavement material.; Pavement Design Manual

resistance temperature detector: RTD; A resistance temperature detector is a sensor used to measure temperature. The sensor is usually made of a metal such as nickel or platinum and whose resistance varies with the temperature. This resistance change is predictable and is stable with time and use.; Manual of Testing Procedures

resistivity: Resistivity decreases with an increase in moisture content of a material until the minimum resistivity is obtained. This minimum resistivity value is defined as the resistivity of the material.; Manual of Testing Procedures

resolution: Resolution is the relative number of pieces of information which defines an image. The number of areas into which a square inch can be divided upon output by an imagesetter. An image scanned at 100 DPI would be defined by pixels 1/100 inch by 1/100 inch in size, or 10,000 per square inch. A 300 DPI laser printer prints an image at 300 DPI, even if the image itself exists digitally at substantially higher resolution.; Communications Manual

resources: Resources include materials, equipment and supplies.; Contract Management Manual

respondent: A respondent is the administration or D/D/O/R responsible for responding to a grievance or an appeal.

responsible district: Responsible district is a Pavement Management Information System (PMIS) term which identifies the district responsible for maintaining a segment of highway. This term is used instead of just “district” because some isolated segments of highway are located in one district but are actually maintained by another (responsible) district.; Pavement Management Information System (PMIS) Users Manual

responsive bidders: Responsive bidders are those who have successfully completed and provided all required forms and documents, made proper acknowledgments, attended any mandatory pre-bid conference, and secured technical prequalification (if applicable). Their bids should be read at the public bid opening.; Letting Manual

rest area: A rest area or safety rest area (SRA)is a TxDOT-operated facility that offers parking, rest room facilities, water, picnic arbors, wireless internet services, etc., for the traveling public. Rest areas are open 24 hours a day, 365 days a year.; Maintenance Division

resting loss emissions: Resting loss emissions are small, continuous seepage and minor leakage of gasoline vapor through faulty connections, permeable hoses and other materials in the fuel system.; Traffic Data and Analysis Manual

restoration (2R) project: Work proposed to restore the pavement structure, riding quality, or other necessary components to their existing cross section configuration. Upgrading roadway components as needed to maintain the roadway in an acceptable condition may be included in the restoration work. The addition of through travel lanes is not permitted under a restoration project.

resurfacing: Resurfacing is the application of an additional surface to an existing base pavement or wearing surface to improve the ride, strength, or safety of the pavement.

retail employment: Retail employment is employment that occurs in businesses classified as retail under the standard industrial classification system.; Traffic Data and Analysis Manual

retainage: Retainage is the percent of each contractor payment retained until contract completion.; Contract Management Manual

retained right: Retained right is the right of a property owner, retained through agreement with the State, to cross a proposed highway or roadway.; Right of Way Collection

retaining walls: Retaining walls are vertical wall used to retain earth. A wall for sustaining the pressure of earth or filling deposited behind it.; Geotechnical Manual

retaliation: Retaliation is the action, harm or injury intentionally inflicted or imposed upon another as an act of revenge. The alleged retaliation may consist of discipline, harassment, difference in treatment, etc. A grievance alleging retaliation may be filed by an employee who believes she or he was retaliated against for involvement in a specified act or participation in a protected activity such as an investigation, opposing discrimination, filing a grievance or whistleblower complaint, or reporting a violation of policy.; Human Resources Manual

retention items: Retention items are items required to be on-hand for emergency use.; Materials And Supplies Management System Manual

retention value: The amount to be deducted from the amount to be paid the owner when he chooses to retain any or all of his improvements. Usually the salvageable value to the acquiring agency.; Real Estate Acquisition Guide for Local Public Agencies

retrieval system: A retrieval system is the equipment (including a retrieval line, chest or full-body harness, wristlets, if appropriate, and a lifting device or anchor) used for non-entry rescue of persons from permit spaces.; Occupational Safety Manual

revenue service vehicle: A revenue service vehicle is the rolling stock (e.g. buses, vans, or railcars) used in providing transit service for passengers. This definition does not include a vehicle used in connection with keeping revenue vehicles in operation, such as a tow truck or a staff car.; Public Transportation Collection

reverse commute program: A reverse commute program includes projects providing transportation services to suburban employment centers from urban, rural and other suburban locations.; Public Transportation Collection

reverse frontage road: See local access road.

revetment: revet; A revetment is a wall or a facing of wood, willow mattresses, steel units, stone, or concrete placed on stream banks to prevent erosion.

revised value: Revised value is a value that has been produced by the change, revision, or modification in the appraisal process to reflect changes in the property or conclusions of the appraiser.; Right of Way Collection

Reynolds number, aeronautic: Reynolds number is a non-dimensional coefficient used as a measure of the dynamic scale of a flow.

rice gravity: Rice gravity is the ratio of the weight of a unit volume of an uncompacted bituminous paving mixture to the weight of an equal volume of gas-free distilled water. Rice gravity is also known as theoretical maximum specific gravity.; Manual of Testing Procedures

ride score: Ride score is a Pavement Management Information System (PMIS) term which describes the ride quality (roughness) of a pavement surface. Ride score ranges from 0.1 (roughest) to 5.0 (smoothest).; Pavement Management Information System (PMIS) Users Manual

right bank: Right bank is that bank of a stream which is on the right when one looks downstream.

right of entry: ROE; An agreement from the owner of a tract or parcel of land specifically authorizing the State (usually including in addition to the State, its contractors, assigns, and the owners of any utility involved with the highway project), the right to enter upon the described tract of land for specific purposes as stated in the agreement. Where such an agreement is without consideration (unpaid), such constitutes just a license to go upon the property for the purposes stated in the agreement, and it may be revocable at the will of the person granting the right. Where a more formal agreement is utilized and payment of more than just nominal consideration is made, such an agreement may be (by its terms) made irrevocable and would constitute more than a license, and would likely be legally considered a construction easement.

right of way: ROW; Real Estate Acquisition Guide for Local Public Agencies; Maintenance Collection

right of way agreement: An agreement stating the responsibility of each party with regard to the acquisition of ROW, relocation assistance, and adjustment of utility facilities.

Right of Way Division: ROW; The Right of Way Division acquires land to build highways and regulates outdoor advertising and junkyards.; Inside TxDOT

right of way line: Right of way line is a legally established line that indicates the boundary between the highway facility and adjacent property owners' holdings.; Right of Way Collection

right of way map: right of way map is a drawing of a proposed or existing improvement showing its relation to adjacent property, the parcels or portions thereof to be acquired, ownerships, and other pertinent information.

rigid pavement: A pavement structure which distributes loads to the subgrade, having as one course a portland cement concrete slab of relatively high-bending resistance. Refer to �flexible pavement.

riprap: Manual of Testing Procedures

risk assessment: Internal Audit Manual; Internal Audit Manual

roadbed: A roadbed is the graded portion of a highway between top and side slopes, prepared as a foundation for the pavement structure and shoulder.; Pavement Design Manual

roadbed material: Roadbed material is the material below the subgrade in cuts and embankments and in embankment foundations, extending to such depth as affects the support of the pavement structure.; Pavement Design Manual

roadbed-mile: A roadbed-mile is a measure of the total length of constructed highway materials in-place or proposed. A roadbed-mile is the same as a centerline-mile except on a divided highway, where the length is doubled to account for the presence of two-way traffic.; Pavement Management Information System (PMIS) Users Manual

roadbed, prepared: See prepared roadbed.

roadeo: Roadeo is TxDOT’s truck driving competition for employees.; Occupational Safety Manual

roadway: Rdwy; Pavement Design Manual; Equipment Manual

Roadway Design System: RDS; Roadway Design System is a software package to design roads or highways. It can include preliminary route location, design, and final design phases. Functions include control survey calculations; compute and plot horizontal and vertical roadway alignments, geometric calculations, compute areas, provide data for preparation of deeds, drawing interchange layouts and right-of-way plans; draw original, design and final cross-sections; design medians, special ditches, and benched slopes; compute earthwork quantities for up to six roadways at one time, draw mass diagram and compute overhaul; perform bridge geometry calculations and preliminary bridge design, store design criteria and design calculations or project tape for future use; can update, revise, or add new design data, and create perspective views.

roadway excavation: Roadway excavation means the required excavation within the limits of the roadway.

roadway gap: A roadway gap is a non-driveable space between two roadway segments created by route deletion, redesignation, removal of a link, or addition of a non-contiguous segment. The reference marker location of the beginning and ending of the gap is exactly the same.; Texas Reference Marker (TRM) System User's Manual

roadway illumination assembly: A raodway illumination assembly is the luminaire and supporting members (pole, mast arm, etc.) with other related lighting equipment attached.; Highway Illumination Manual

roadway illumination details: RID; Roadway illumination details are the TxDOT standard sheets showing specifications for roadway illumination to be used with TxDOT standard specification Items 610, 611, 612, and 656. The details are contained in the Traffic Operations Standard Plans.; Highway Illumination Manual

roadway improvement: A roadway improvement is construction or reconstruction made to the roadway cross-section.; Safe Routes to School Program Guidelines

rock: Rock is a mass of solid, naturally occurring material from an in-situ deposit, excluding conglomerates. The formation may or may not be laminated.

rolling: Rolling is the process of applying pressure to a lift of material to attain desired compaction.

ROSCOE PDSE Library Facility: The ROSCOE PDSE Library Facility (RPDS/PDSE) consists of the ROSCOE Programming Facility (RPS) program, RPSD and mainframe partitioned data sets (PDSEs) that are used to provide "libraries" for storing data that would otherwise be stored in ROSCOE libraries.; Source: Information Security Manual

ROSCOE (Remote Operating System Conversational Operating Environment) Programming Facility: RPF; Within the ROSCOE terminal package a facility known as ROSCOE Programming Facility exists for performing repetitive functions. This allows the user to write a series of instructions (which are actual ROSCOE commands) and call forth their execution.

ROT‑13: ROT 13 is a form of encryption that can be used to make all or part of a Usenet posting unreadable. Others who have the encryption key can decipher the message.; Information Technology and Services Manual

roughness coefficient: n; A roughness coefficient is a factor in the Kutter, Manning, and other flow formulas representing the effect of channel (or conduit) roughness upon energy losses in the flowing water.

route over or under: A bridge at intersecting highways is defined as an underpass or overpass based on the inventory hierarchy of the two routes. This description is used where required on all forms, plans, etc. The �hierarchy of Texas highways is: Interstate, US, SH, State Loops or Spurs, FM/RM, County Roads (CR), and Business Routes (BR). The lower route number takes precedence if the highways are of equal hierarchy. Examples are:; Bridge Inspection Manual

router: A router is a computer that transfers data between two networks using the same set of protocols.; Source: Information Security Manual

route realignment: Route realignment is roadway reconstruction that causes the alignment and length of the route to change; deleting the realigned route segment from the route creates a gap in the roadway in TRM.; Texas Reference Marker (TRM) System User's Manual

route study: A route study compares and analyzes alternative route alignments within a transportation corridor with the primary purpose of determining a preferred route alignment. The study may be done after or as part of a �feasibility study.

rule: A rule is any agency statement of general applicability that implements, interprets or prescribes law or policy, or describes the procedure or practice requirements of an agency. A rule can be either a policy or procedure.

rule procedures: Rule procedures are statements that describe the action or practice required by an agency. These procedures are effective for external parties only when published according to the Administrative Procedure and Texas Register Act (APTRA).

running loss emissions: Running loss emissions are evaporated gasoline emissions occurring while a vehicle is driven due to the heating of the fuel and fuel lines.; Traffic Data and Analysis Manual

runoff: Runoff is that portion of precipitation that makes its way toward waterways, lakes, or oceans as surface or subsurface flow.

runoff coefficient: Runoff coefficient the fraction of total rainfall that will appear as runoff.

rural minor collector: A rural minor collector is a road that collects traffic from local roads, bring all developed areas within a reasonable distance of a collector road, provide service to the remaining smaller communities, and link the locally important traffic generators with their rural hinterland.; Transportation Planning and Programming Collection

rural road: A rural road is a road, street, way, highway, thoroughfare, or bridge that is located in an unincorporated area and that is not privately owned or controlled, any part of which is open to the public for vehicular traffic, and over which the state or any of its political subdivisions have jurisdiction.; Right of Way Manual

Rural Transit Assistance Program: RTAP; The Rural Transit Assistance Program is a program of research, training, technical assistance and other support services to meet the needs of transit agencies serving nonurbanized areas.; Public Transportation Collection

Rural Transit District: RTD; A Rural Transit District is a political subdivision of the state that provides and coordinates rural public transportation within its boundaries in accordance with the provisions of Transportation Code, Chapter 458.; Public Transportation Collection

Rural Transportation Improvement Program: The Rural Transportation Improvement Program is a staged, multiyear, intermodal program of transportation projects that is developed by the department, in consultation with local officials, for areas of the state outside of the metropolitan planning area boundaries. The rural TIP includes a financially constrained plan that demonstrates how the program can be implemented.; Transportation Planning and Programming Collection

rut: Pavement Management Information System (PMIS) Users Manual; Maintenance Collection