Glossary of Acronyms and Terms
Definitions: From G to I
Geometric Design – The arrangement of the visible elements of a road, such as alignment, grades, sight distances, widths, slopes, etc.
Georgia Environmental Policy Act of 1991 (GEPA) – This act (Senate Bill 97) passed during the 1991 session of the Georgia Legislature, requires the evaluation and disclosure of environmental effects of proposed state (funded) actions. In general, a proposed action by a government agency must be assessed by the responsible official (the Commissioner is the responsible GDOT official) of that agency to determine and document whether or not the proposed action may significantly affect the quality of the environment. In the event of a determination of a significant adverse effect, the act requires an evaluation of the pros and cons of alternatives that would avoid the adverse impact as well as measures to minimize harm.
Grade – (1) The profile of the center of the roadway, or its rate of ascent or descent. (2) To shape or reshape an earth road by means of cutting or filling. (3) Elevation.
Grade Separation – A structure which provides for traffic to pass over or under another road or railroad.
Gutter Width – Distance between the pavement edge of a street and the face of the curb; a typical gutter width is two feet.
Horizontal Alignment – Horizontal geometrics of the roadway.
Horizontal Curve – A curve or transitional by means of which a road can change direction to the right or left.
ISTEA (Intermodal Surface Transportation Equity Act) - “Signed into law by President Bush in December 1991, ISTEA establishes a new vision for surface transportation in America.” (National Transportation Library, 1991). An online summary of ISTEA is available online at http://ntl.bts.gov/DOCS/ste.html
Isometric – A three-dimensional drawing that does not use perspective. An isometric drawing shows two sides of the object and the top or bottom of the object.
