A	back to top
aesthetic   aesthetics; refers to the visual quality of structural or architectural elements and settings. AADT   Average Annual Daily Traffic AASHTO   American Association of State Highway and Transportation Officials (develops design guidelines for transportation facilities) abutment   vertical end supports of a bridge structure upon which the girders bear and terminate. (see also: substructure, pier) ACC/MVM   Accidents Per Million Vehicles Miles Traveled ACOE   United States Army Corp of Engineers; is the agency bound with the responsibility of enforcing Federal regulations governing waters of the United States, typically reviewing findings for wetlands and water quality studies (see also: COE; USACE). ADT   Average Daily Traffic (see also: average daily traffic) advertisement   invitation by CDOT to contractors to bid on construction projects, usually officially announced or 'advertised' in newspapers. (see also: award; bid) alternatives   various transportation options developed and analyzed during an EA or EIS study process. alternative screening   Evaluation of a full range of possible transportation alternatives to identify the most reasonable alternatives for further consideration. APCD   Air Pollution Control Division APE   Area of Potential Effect; geographical area established by the project team under Federal guidelines within which direct or indirect environmental effects could be expected to occur and to identify specific locations for further investigation and documentation. (see also: section 4(f) ) apparent low bidder   the bid is 'apparent' until certain reviews are completed to make sure that the bidder has the appropriate resources available to meet the project requirements and has understood the major work elements.(see also: advertisement; bid; and award) arterial roadway or street   high volume local roadway primarily carrying through traffic on a generally continuous route. Its primary function is to provide relatively uninterrupted travel through an urbanized area. In many cases, access to homes and businesses is limited. Arterial roadways can be further delineated as major or minor arterials depending on traffic volume and capacity. at-grade crossing   location where crossing traffic shares the same elevation or "grade". Typically used to describe a common rail /roadway crossing or a roadway intersection. (see also: grade separation) auxiliary lane   lane(s) in addition to the through-traffic lanes that accommodate speed changes, weaving, and maneuvering of entering and leaving traffic. average daily traffic   ADT; total volume of vehicles during a given time period, divided by the number of days in the time period. avoidance alternatives   alternatives that avoid use of section 4(f) protected properties which can only be eliminated if they are "determined to present unique problems or unusual factors or if they would produce costs, environmental impacts or community disruption reaching extraordinary magnitudes". (see also: section 4(f) ) award   selection of a contractor to do work for CDOT through the advertisement and bid process. The 'award' of the contract (see also: advertisement; bid) AWDT   Average Weekday Daily Traffic; average daily traffic further delineated by weekday or workday to specify commuter traffic.
B	back to top
barrier   physical separator between elements erected for specific purposes such as blocking noise or channeling traffic (see also: noise barrier; sound barrier; traffic barrier). BEA   Bureau of Economic Analysis bearing device   mechanical elements upon which a bridge superstructure rests or bears on the substructure allowing movements from temperature expansion and contraction and rotation from load deflections. bid   process by which construction contractors price or 'bid' a project with the contract being awarded to the lowest bidder (see also: advertisement; award; final design). BLM   Bureau of Land Management BMP   Best Management Practices BNRR   Burlington Northern Railroad; pre-merger name. (see also: BNSF) BNSF   Burlington Northern Santa Fe; railroad. Burlington Northern railroad name after acquisition of Santa Fe Rail Road. (see also: BNRR) BRT   Bus Rapid Transit. Dedicated corridor on system stations similar to light rail, except utilizing standard, rubber tired, highway bus coaches.
C	back to top
CAAA   Clean Air Act Amendments Categorical Exclusion   catex; cat-x; category of project action which a federal agency (such as FHWA) identifies in its NEPA procedures, that do not individually or cumulatively have a significant effect on the environment, excluding them from the need for an EA or EIS process. (see also: NEPA; EA; EIS ). CCD   City and County of Denver CD Road   Collector Distributor Road (see also:collector distributor road ) CDOT   Colorado Department of Transportation CDOW   Colorado Division of Wildlife CDPHE   Colorado Department of Public Health and Environment cloverleaf interchange   common interchange configuration deriving its name from the pattern created by the ramps. "Clovers" are designed to maximize traffic capacity and flow but require more space than a diamond interchange. They are known as "full" when all four leaves are present and "partial" when the configuration is combined with other types of interchange designs. (see also: diamond interchange; trumpet interchange). CNHP   Colorado Natural Heritage Program CO   Carbon Monoxide COAHP   Colorado Office of Archaeology and Historic Preservation COE   United States Army Corps of Engineers; is the agency bound with the responsibility of enforcing Federal regulations governing waters of the United States, typically reviewing findings for wetlands and water quality studies (see also: ACOE; USACE). COG   Council of Governments; organization of local municipalities established to cooperatively plan community growth and therefore are particularly involved in transportation issues. collector distributor road   road that is next to but separate from the freeway used to eliminate weaving on the mainline freeway lanes and reduce the number of entrance and exit points on to the throughways. Similar to continuous frontage roads except access to abutting property is not permitted. (see also: freeway; frontage road) collector street   local street that is used to improve traffic flow by collecting traffic from several local streets and directing that traffic to an arterial street. column   (see: pier column) conceptual design   idea or feasibility phase of the design process during which various alternatives are developed and tested. During this phase various environmental and engineering issues are identified and accounted for prior to advancing a Preferred Alternative into the preliminary and final design phases. (see also: preliminary design; final design) Cultural Resources   Historical, Archeological and Paleontological sites and or artifacts of cultural value. cumulative effects   effects that are the result of incremental impacts of an action, when added to other past, present and reasonably future actions regardless of which agency or person undertakes the action. CWA   Clean Water Act CWQCC   Colorado Department of Water Quality Control Commission
D	back to top
dBA   Decibels; average noise fluctuations over an hour. deck   concrete structural surface of a bridge supported by the girders which can include a sidewalk, vehicle lanes and medians. A bridge deck may include an asphalt wearing surface to protect the reinforcing steel in the concrete from winter road salt. design speed   or maximum design speed; the maximum safe speed that can be maintained under ideal conditions for a given section of highway. A desired design speed is typically set to determine particular design criteria for highway geometry. The design speed is ideally 10 mph greater than the intended posted speed limit as a margin of safety. (see also: posted speed) DHV   Design Hour Volume diamond interchange   common interchange configuration deriving its name from the pattern created by the ramps. Diamonds can be described as "small", "tight", or "compressed" if they are designed to minimize space requirements, or "partial" when the configuration is combined with other types of interchange designs. (see also: cloverleaf interchange; trumpet interchange). directional ramp   a one way roadway that does not deviate greatly from the intended direction of travel. Example: Eastbound 6th Avenue to Northbound I-25. DLA   Department of Local Affairs DOT   Department of Transportation DOW   Division of Wildlife (Colorado) DRCOG   Denver Regional Council of Governments
E	back to top
EA   Environmental Assessment EB   eastbound direction of travel. EIS   Environmental Impact Statement (see also: environmental impact statement) EO   Environmental Overview; typically an EO is completed for the Policy Directive 1601 to analyze the physical, social, and environmental impacts associated with the proposed improvements. EO   Executive Order Environmental Impact Statement   EIS; detailed statement required by NEPA when an agency (such as FHWA) proposes a major federal action significantly affecting the quality of the environment. (see also: NEPA) environmental justice   pursuit of equal justice and equal protection under the law for all environmental statutes and regulations without discrimination based on race, ethnicity, and/or socioeconomic status, includes a guarantee of equal access to relief and meaningful community participation with government and industry decision-makers. expansion device   mechanical joint at the end of a bridge structure deck to absorb the movement caused by temperature expansion and contraction and load deflection. EPA   Environmental Protection Agency ESA   Endangered Species Act
F	back to top
FEMA   Federal Emergency Management Agency FHWA   Federal Highway Administration; part of the United States Department of Transportation; provides and administers financial assistance to the States to construct and improve the National Highway System and coordinates compliance with federal safety and environmental regulations. final design   Final phase of the design process during which a final plan and specification package is prepared. This package, also known as a 'bid' package, is used by construction contractors to price and build a project (see also: bid). FIR   Final Internal Review; final CDOT review of project (30%) preliminary plans prior to proceeding with final design. flyover   an interchange movement or roadway that goes over the freeway. FOR   Final Office Review; final CDOT review of project (90%) final plans prior to proceeding with completion of final plans and bid documents. FRA   Federal Railroad Administration freeway   high-speed roadway with controlled access and no at-grade intersections. FTA   Federal Transit Administration
G	back to top
geometric deficiencies   characteristics, both horizontally and vertically, that do not meet current design standards. (examples: road curvature, sight distance, shoulder widths) girder   horizontal support members of a bridge structure spanning between abutments and over piers, depending upon the length of the bridge, to support the deck. GOCO   Greater Outdoor Colorado grade separation   location where a bridge (overpass) is used to separate crossing traffic by creating an elevational or "grade" difference which will allow one movement to pass over the other. (see also: at-grade crossing) GRP   Ground Penetrating Radar; a non-destructive method of locating subsurface clusters of objects using ultrahigh-frequency radio waves. GPR is frequently used to determine the presence of potential historical and archeological artifacts.
H	back to top
HCM   Highway Capacity Manual; FHWA manual for highway capacities used as a guideline to uniformly make future traffic volume projections. highway capacity   maximum number of vehicles per hour which can reasonably traverse a road segment during current roadway and traffic conditions. HPC   Historic Preservation Commission horizontal alignment   horizontal geometry; alignment of a roadway horizontally, determining degree of curves, superelevation, and the lengths of, or, distances between these features based upon parameters such as design speed, sight distance, and driver comfort.(see also: vertical alignment; superelevation) HOV   High Occupancy Vehicle
I	back to top
independent utility   federal funding term describing a project which can stand alone, when completed, requiring no additional work or funding to be functional for a given specific use. infrastructure   basic framework or permanent installations of the highway transportation system. interchange   Location where two converging roadways are grade separated by bridge structure with ramps connecting various directions of travel between the roadways. (see also: intersection; overpass; ramp; grade-separation) intersection   location where two converging roadways meet and cross at-grade (see also: interchange; overpass). interstate   federally designated freeway that is typically continuous through more than one state. (see also: freeway) ISTEA   Intermodal Surface Transportation Efficiency Act
J	back to top
K	back to top
L	back to top
lane balance   use of additional lanes, other than through lanes, to improve traffic movements between interchanges. Aids in accommodating on and off movements without interrupting the through lane traffic. loop ramp   a free-flow ramp that utilizes a circular path. Example: Northbound I-25 to Westbound 6th Avenue. LOS   Level of Service; graduated scale describing traffic congestion conditions established by the Transportation Research Board where (A is best and F is worst). LUST   Leaking Underground Storage Tank
M	back to top
Mitigation   various measures to minimize harm to NEPA and USDOT Section 4(f) protected resources, due to transportation improvements. (see also: Section 4(f);and MOA) MOA   Memorandum of Agreement; agreement on mitigation efforts to resolve adverse effects to historic properties under the National Historic Preservation Act. mph   miles per hour MPO   Metropolitan Planning Organization MSE   Mechanically Stabilized Earth; engineered system by which soil is reinforced using overlapping layers of plastic or metallic mesh and earth. MSE is used to create vertical or near vertical walls of soil for temporary purposes or finished permanently with concrete or masonry facings. MUTCD   Manual on Uniform Traffic Control Devices
N	back to top
NAAQS   National Ambient Air Quality Standards NAC   Noise Abatement Criteria NAFTA   North American Free Trade Agreement; trade agreement between Mexico, Canada and the United States intended to increase economic interaction. NAFTA is expected to increase truck and rail traffic on major north/south corridors particularly in western states. National Environmental Policy Act   NEPA; federal legislation that establishes environmental policy for the nation. It provides a framework for federal agencies to prevent environmental damage and contains procedures to ensure that federal agency decision makers take environmental factors into account. NB   Northbound direction of travel. NEPA   National Environmental Policy Act (see also: National Environmental Policy Act) NHD   National Historic District NHP   National Heritage Program NHPA   National Historic Preservation Act NHS   National Highway System no-action alternative   no change alternative must be analyzed for all projects as a baseline for analysis of the proposed project action alternatives. NOI   Notice of Intent (see also: Notice of Intent) noise abatement  introduction of barriers or other measures to reduce the effects of noise created by roads and trains. (see also: noise barrier; sound barrier). noise barrier   Barrier or wall (noise wall) erected to block or deflect noise (see also: sound barrier). Notice of Intent   announces to the public and to interested agencies that a project is being developed and that an EIS will be prepared. NPDES   National Pollutant Discharge Elimination System. NPS   National Park Service NRCS   Natural Resource Conservation Service. NRHP   National Register of Historic Places NTP   Notice-to-Proceed; official notification to a contractor that permission is granted to begin work under a specific contract or task order.
O	back to top
OAHP   Office of Archeology and Historic Preservation offset urban interchange   a SPUI that is offset from the intersection of the freeway and roadway. Example: I-225 and Alameda. OES   Office of Environmental Service OIS   Oil Inspection Section; responsible for registering, inspecting and safe removal permitting of underground storage tanks. O&M   Operation and Maintenance OPS   Colorado Department of Labor and Employment, Division of Oil and Public Safety overpass   location where two converging roadways are grade separated by bridge structure and no ramps are provided to connect the roadways (see also: interchange; intersection).
P	back to top
park-n-Ride   p-n-R; RTD transit station where commuters may park their automobiles and board buses or light rail vehicles for travel to their final destination. (see also: Regional Transportation District) peak-hour traffic   volume of traffic during the highest volume one hour period, usually during rush hour, that reflects conditions that should be used for design. pier   vertical intermediate supports of a bridge structure located between the abutments consisting of a footing, columns and a cap beam. (see also: substructure, abutment) pier cap   or cap beam: horizontal member of a pier supporting the girders. One or more columns support the pier cap. (see also: pier; pier column; girders) pier column   vertically supporting member of a pier carrying the pier cap. A pier may have one or more pier columns. (see also: pier; pier cap) PM   Project Manager PM10   Particulate Matter 10; Particulate matter less than ten microns diameter on a scale categorizing airborne particles. p-n-R   park-n-Ride (see also: park-n-Ride) Policy Directive 1601   CDOT Policy Directive 1601; a CDOT policy that requires that all requests for new interchanges and improvements to existing interchanges on major state highways be reviewed and evaluated in a consistent manner through the use of established guidelines. posted speed   the maximum speed limit posted for any given section of a highway. The posted speed limit is ideally 10 mph less than the maximum design speed. (see also: design speed) PR   Public Relations Preferred Alternative   transportation option determined to be acceptable according to the purpose and need of the project. (see also: purpose and need). preliminary design   first phase of the final design process during which a 30% plan package is prepared. This package is used by CDOT to troubleshoot the overall scope of a project prior to more the detailed final design. (see also: conceptual design; final design) Project Feasibility Study   PFS; the second step required by CDOT Policy Directive 1601; a document that addresses the precise location and conceptual design configuration for a new interchange or interchange improvements, documents traffic forecasts and their associated impacts, and identifies both state highway system and off-system improvements needed to accommodate the projected traffic. PUC   Public Utilities Commission Purpose and Need   well documented description of the reason that a given project is necessary, states the projects goals and drives the selection of the range of alternatives.
Q	back to top
QC   Quality Control
R	back to top
ramp   inclined roadway connecting different levels of grade-separated roadways typically at interchanges. (see also: interchange) RAQC   Regional Air Quality Council raptor   any species of predatory bird. RCRA   Resource Conservation and Recovery Act REA   Re-evaluated Environmental Assessment Record of Decision   ROD; public document that reflects the final decision, rationale behind that decision and commitments to monitoring and mitigation. reinforcing steel   system of steel bars (rebar) cast within concrete structures to compliment the excellent ability of concrete to resist compression by adding excellent steel ability to resist tension. REQA   Regional Environmental Quality Advisor (NEPA Representative). Right-of-Way  (see: ROW) riparian   relating to or living on the bank of a natural watercourse. ROD   Record of Decision. (see also: Record of Decision) ROW   Right-of-Way; Public land dedicated for use in providing public roadways. RR   Rail Road RTD   Region Transportation Director RTD   Regional Transportation District; local transit authority responsible for operating the Denver Metro area bus and light rail systems.
S	back to top
SADT   Summer Average Daily Traffic SB   Southbound direction of travel. SCS   Soil Conservation Service (United States) scoping   identification of issues and dialogue with affected agencies and interested public. SHPO   State Historic Preservation Officer or State Historic Preservation Office. Section 4(f)   Section 4(f) of the Department of Transportation Act of 1966 (49 U.S.C. 303), states that “it is the policy of the United States Government that special effort should be made to preserve the natural beauty of the countryside and public park and recreation lands, wildlife and waterfowl refuges, and historic sites.” The FHWA determines applicability and compliance of Section 4(f) regulations on transportation projects. (see also: FHWA) service life   expected or actual term a facility such as a bridge structure or a roadway remains in use. SIP   State Implementation Plan. sound barrier   barrier or wall (sound wall) erected to block or deflect noise. (see also: noise barrier) spall   spalling; condition where finished surface concrete separates from the main body of concrete in patches caused by age deterioration, freeze thaw action, vibration, moisture and corrosive chemicals span   distance between the supports of a bridge, sometimes used to refer to the structural members being supported or the section of a bridge between supports ( i.e. a multi-span bridge) specifications   also known as special provisions; detailed written description of procedures, processes, and quality of workmanship, provided to supplement the project plans in addition to CDOT standard specifications.(see also: standard specifications) SPUI   Single Point Urban Interchange. Similar to a diamond interchange, except all left turns are handled at one signalized intersection and all right movements are free-flow. Example: Belleview and Santa Fe. standard specifications  detailed written description of procedures, processes, and quality of workmanship, published periodically in book form by CDOT for use on all projects.(see also: specifications) STIP   State Transportation Improvement Plan substructure   general term referring to the group of major supporting elements of a bridge including the abutments, piers, and footings.(see also: superstructure) superelevation   the banking or tilt given to a curved roadway (the outside of the curve is higher than the inside) to counteract the effect of centrifugal force of a vehicle traveling at an assumed design speed.(see also: design speed) superstructure   general term referring to the group of major horizontal bridging elements of a bridge including the girders and deck.(see also: substructure) System Alternatives   project alternatives developed for the entire highway and interchange system for I-25 from Logan Street to 6th Avenue and along 6th Avenue from I-25 to Federal Boulevard. System Feasibility Study   SFS; the initial step required by CDOT Policy Directive 1601; a document that addresses general traffic impacts for a new interchange or interchange improvements in the context of the regional transportation facilities and the local arterial roadway system and shows if there would be benefits to the regional transportation network.
T	back to top
TAZ   Traffic Analysis Zone TCP   Traffic Control Plan TDM   Traffic Demand Management TDP   Transportation Development Program T&E   Threatened and Endangered TIP   Transportation Improvement Plan TM   Transportation Management TOD  Transit Oriented Development TODS  Tourist Oriented Directional Signs; CDOT program responsible for installation of tourist services, historic marker, and scenic byway signage. TPR  Transportation Planning Region traffic barrier   barrier erected to protect traffic from roadside hazards, edges of bridge structures and walls or to separate opposing directions of traffic. traffic flow   characterized by three elements; volume (vehicles per hour), speed (miles per hour), and density (vehicles per mile). TREX   Transportation Expansion Project TSM   Transportation System Management
U	back to top
UDFCD   Urban Drainage and Flood Control District UPRR   Union Pacific Railroad urban design   term used describe the process of determining the character (aesthetics, materials, landscaping, lighting and other amenities) associated with a project in built-up areas. USACE   United States Army Corps of Engineers; is the agency bound with the responsibility of enforcing Federal regulations governing waters of the United States, typically reviewing findings for wetlands and water quality studies (see also: COE; ACE). USDA   United States Department of Agriculture USDOT   United States Department of Transportation USEPA   United States Environmental Protection Agency (also: EPA). USFWS   United States Fish & Wildlife Services UST   Underground Storage Tank (see also: LUST).
V	back to top
value engineering   independent engineering review of a given design specifically aimed at determining its cost efficiency and, if possible, offer cost saving alternatives. VdB   Vibration Decibel: Average Vibration Fluctuations Over an Hour vertical alignment   vertical geometry; alignment of a roadway vertically, determining grades, crests, valleys, and the lengths of, or, distances between these features based upon parameters such as design speed, sight distance, drainage and driver comfort.(see also: horizontal alignment) viaduct   bridge consisting of a series of similar spans carrying a roadway or railroad over valleys, waterways or other roads or railroads.(see also: overpass; span) VMT   Vehicle Miles Traveled VMT   Vehicle Miles Traveled VPD   Vehicles Per Day VPH   Vehicles Per Hour
W	back to top
WADT   Winter Average Daily Traffic WB  westbound direction of travel. wearing surface   relatively easily replaceable material placed onto a bridge deck to absorb the majority of the deterioration caused by traffic and winter salting. The material can be specially formulated concrete or asphalt. weave   weaving; crossing of traffic streams which are entering and exiting a highway system between the ramps of adjacent interchanges. weave distance   space available between the gores of ramps from adjacent interchanges for the crossing or weave of traffic entering and exiting the system. Wetlands   land area where at least 50% of the vegetation is hydrophic vegetation, has wetland hydrology and hydric soils. Wetlands are under jurisdiction of the USACE. WQCC   Water Quality Control Commission.
X	back to top
Y	back to top
Z	back to top

A Colorado Department of Transportation Project Website
Copyright © Colorado Department of Transportation
Felsburg Holt & Ullevig