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Abatement
A reduction in degree of intensity of a substance or quantity.
Abutment
Substructure supporting the end of a span, retaining or supporting the approach embankment.
Adverse Effect
An effect is considered adverse when an undertaking may alter the characteristics that make a property eligible for the National Register by diminishing its integrity of location, design, setting, materials, workmanship, feeling, or association.
Adverse effects may be indirect as well as direct, may include reasonably foreseeable effects that may occur later in time or at a distance, and may be cumulative.
Affected Environment
The physical features, land, area, or areas to be influenced, affected by or created by an alternative alignment under consideration; also includes various social and environmental factors and conditions pertinent to an area.
Alignment
The line that represents the location of a highway being considered as a new alignment alternative.
Alignment Studies
A general term for engineering work involving the vertical and horizontal positioning, adjusting and refining, and comprehensive evaluation of a trial line or lines through a selected study corridor. All relevant features, controls, travel desires, impacts, benefits and costs are taken into account in these studies. Alignment studies are typically performed to assess the relative feasibility of a proposed transportation facility linking two identified points.
Alternative
One of a number of specific transportation improvement proposals, alignments, options, design choices, etc. in a study. Following detailed analysis, one improvement alternative is chosen for implementation. Sometimes, the term "alternate" is used interchangeably with "alternative."
Alternatives Analysis
Preliminary engineering and environmental studies of a wide range of alternatives. The objective is to reduce the number of alternatives for more detailed study, and then, after substantial and detailed engineering and environmental studies, to select a preferred alternative.
Annual Average Daily Traffic (AADT)
The estimate of typical daily traffic on a road segment for all seven days of the week over the period of one year.
At-Grade Intersection
An intersection where all roadways join or cross at the same level.
Average Daily Traffic (ADT)
The average 24-hour volume, being the total volume during a stated period divided by the number of days in that period. Unless otherwise stated, the period is a year
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Capacity
The maximum rate of traffic flow that can be expected to pass a certain point; usually expressed in vehicles per hour.
Congestion
The level at which transportation system performance is no longer acceptable to the traveling public due to traffic interference.
Corridor
An area of variable width between two points. In highway work, corridors are defined areas where the needs for improvements are studied.
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Design Year
The year for which a roadway facility is designed, normally 20 years in the future, taking in consideration projected volumes of traffic.
Detailed Alternatives
Alternatives that have undergone intensive engineering and environmental analyses in a process that will lead to selection of a preferred alternative.
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Effect
Alteration to the characteristics of a historical property qualifying it for inclusion in or eligibility for the National Register.
Environmental Impact Statement (EIS)
A written statement containing an assessment of the anticipated significant effects, both positive and negative, which a prospective agency decision may have upon the quality of the human environment, as provided in the National Environmental Policy Act of 1969 (NEPA).
Expressway
A divided arterial highway for through traffic with full or partial control of access and generally with grade separations at major intersections.
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Final Design Phase
Includes preparation of final right-or-way plans for property acquisition and construction plans and specifications for bidding contracts.
Final Environmental Impact Statement (FEIS)
All substantive comments and questions received at the Public Hearing and on the DEIS are addressed in this document prepared by transportation agencies. Other studies are done, as needed, to address comments and questions. The document is then submitted to the Federal Highway Administration, with a recommended alternative, for approval.
Floodplain
Any flat, or nearly flat lowland that borders a stream and is covered by its waters at flood stage. For the purpose of this document, floodplain is used in reference as defined by FEMAÕs 100-year floodplain.
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Geographic Information System (GIS)
A computerized system of compiling, presenting and analyzing geographic based data. Map images of the road network can be overlaid with land use zoning information, environmental concerns, census data, and other useful information.
Grade-Separated Intersection
- A crossing of two highways or other transportation facilities, at different levels.
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Hazardous Waste
Waste identified by characteristics, source or specific substance as found in 25 PA Code Chapter 75, Subchapter D and Code of Federal Regulations Title 40, Chapter 261. A hazardous waste may: 1) cause or significantly contribute to an increase in mortality or morbidity in either an individual or the total population; and 2) pose a substantial present or potential hazard to human health or the environment when improperly treated, stored, transported, disposed or otherwise managed.
Historic Property
Any prehistoric or historic district, site, building, structure, or object included in, or eligible for inclusion in, the National Register of Historic Places maintained by the Secretary of the Interior.
Historic Resource
(also Historic Property) - Building, site, district, object, or structure evaluated as historically significant.
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Impacts
Positive or negative effects upon the natural or human environment resulting from transportation projects.
Interchange
A system of interconnecting roadways in conjunction with one or more grade separations, providing for the movement of traffic between two or more roadways on different levels.
Intermittent Stream
A stream that carries water a considerable portion of the time, but which ceases to flow occasionally seasonally.
Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991
Presents a series of social, environmental and energy factors, which promote balance and diversity, to be considered in the transportation planning and project selection process.
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Level of Service (LOS)
A qualitative rating of the effectiveness of a transportation component (such as a freeway or a signalized intersection) measured in terms of operating conditions. The Highway Capacity Manual identifies operating conditions ranging from "A" to "F", briefly described below for signalized intersections:
- LOS A - Excellent traffic flow, favorable progression, most vehicles do not stop.
- LOS B - Very good traffic flow, short delays, more vehicles stop than under LOS A causing higher levels of delay.
- LOS C - Traffic flow is still good, but the number of vehicles stopping is significant. Many vehicles still proceed without stopping.
- LOS D - The influence of congestion becomes noticeable. Few vehicles advance through the intersection without stopping.
- LOS E - The limit of acceptable delay for many agencies. Virtually no vehicles proceed without stopping.
- LOS F - Traffic volume exceeds available capacity. All vehicles must stop at least once, and possibly must wait through several signal cycles before proceeding.
Limited Access
A term to describe either a partially or fully access-controlled highway abutting property.
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Major Investment Study (MIS)
A study designed to provide decision makers with better, more complete information regarding costs, benefits, and impacts of alternative ways to solve transportation problems.
Median
The portion of a divided highway separating the traveled ways for traffic in opposite directions.
Metropolitan Planning Organization (MPO)
The agency designated by the Governor (or Governors in multi-state areas) to administer the federally required transportation planning process in a metropolitan area. An MPO must be in place in an urbanized area with a population over 50,000. The MPO is responsible for the 20-year long range plan and the transportation improvement program.
Mitigation
The replacement of natural features that have been lost or reduced in value.
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National Environmental Policy Act (NEPA)
Federal legislation that established the environmental policy for the nation. It requires federal agencies to utilize a systematic, interdisciplinary approach to agency decision-making. A basic tenet of the act is that wise decisions are possible only when alternative actions are developed and their consequences evaluated. Provisions in the legislation additionally ensure that environmental information is available to public officials and citizens before actions are taken. The NEPA process is intended to help public officials make decisions that are based on an understanding of environmental consequences, and take actions that protect, restore, and enhance the environment.
National Register of Historic Places
A list maintained by the U.S. Department of the Interior of historic and prehistoric sites that have local, state, or national significance.
Natural Resources
Land, fish, wildlife, drinking water supplies and other assets belonging to, maintained by, or otherwise controlled by the federal, state, or local government.
No Adverse Effect
The undertaking will have no adverse effect when effects do not meet the criteria of adverse effect or when the undertaking is modified or conditions are imposed to ensure that potential adverse effects are avoided.
No Build Alternative
An alternative used as a comparison for other alternatives considered. This alternative does not provide for any major improvements to the existing roadway system. This alternative would only include routine maintenance improvements such as resurfacing, traffic lane marking and minor lane widening to the existing highway system.
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Parkway
A public roadway with a landscaped right-of-way, that may be divided by a grassy median.
Peak Hour
The one-hour period of a typical day during which traffic volumes are the greatest.
PENNDOT 10-Step Process
The preliminary design phase of PENNDOT's Transportation Project Development Process. The 10-Step Process is the framework for the involvement of resource agencies and the public in the environmental and alternative evaluations of project studies.
Preliminary Alternative
A conceptual alternative that meets the projectÕs stated purpose and needs and has been carried forward for further development and evaluation.
Preliminary Design
The engineering and environmental studies associated with the development and comparison of alternate locations, alternate alignments, detailed analysis, on-going public and agency interaction, project review, and final selection of a project alternative.
Public Hearing
Formal meeting required to complete the NEPA public involvement requirements. Testimony at the hearing is made part of the official record and is reviewed by state and federal agencies before the preparation of an FEIS.
Public Meeting
An informal meeting held by the Department of Transportation at any level of project development to provide the public with updated information.
Purpose and Need
The project purpose is a broad statement of the overall intended objective to be achieved by a proposed transportation facility, normally defined in a few sentences. The need is a more detailed explanation of the specific transportation problem(s) or deficiencies which have generated the search for improvements.
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Record of Decision (ROD)
FHWA's final decision and explanation regarding identification of the selected alternative.
Right-of-Way
Land acquired by purchase, gift, or eminent domain in order to build and maintain a public road.
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Section 4(f)
A portion of the Department of Transportation Act of 1966 that states "special effort should be made to preserve the natural beauty of the country side and public park and recreation lands, wildlife and waterfowl refuges, and historic sites." Section 4(f) applies to all historic sites, but only to publicly-owned parks, recreation areas, and wildlife and waterfowl refuges.
Single-Occupancy Vehicle (SOV)
A car or truck with no passengers.
Structure
Bridge mainline structure refers to elevated sections of the alignment that cross over other roads, railroad tracks or major streams.
Study Area
The specific area under investigation for an individual environmental study.
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Traffic Calming
According to PennDOT's traffic calming manual, "traffic calming measures are mainly used to address speeding and high cut-through traffic volumes on neighborhood streets. These issues can create an atmosphere in which non-motorists are intimidated, or even endangered, by motorized traffic."
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Vehicles Per Day (VPD)
The number of vehicles that have been counted passing a spot in a 24-hour period.
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Wetland
Lands frequently inundated or saturated with water. An important natural resource that provides flood control, pollution control and habitat for fish, birds and mammals and aquatic life as well. Wetlands are more commonly known as marshes, bogs, swamps, wet meadows and shallow ponds.
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