Civil Engineering Knowledge Center
Expertise in all aspects of the built environment.
Our civil engineering practice is engaged throughout the life cycle of a project: from planning, design, and permitting, through construction and operations. With this glossary, we hope to convey our expertise to a broader audience while continuing to enhance communications with our clients.
Highway alignment includes horizontal alignment and vertical alignment. The projection of highway alignment in the horizontal plane is termed as the horizontal alignment, and the projection of highway alignment in the vertical plane is called vertical alignment. Alignment must be selected in such a way that the overall cost during construction, operation and maintenance, and right-of-way impact is minimum.
Roadway rehabilitation consists of resurfacing, restoration, and rehabilitation (3R) work consisting of structural enhancements that extend the service life of an existing pavement and/or improve its structural capacity. Rehabilitation techniques include restoration treatments and/or structural overlays.
To comprehensively rebuild to a new condition with current criteria. Used to rebuild subgrade, roadway base, new roadway surface, roadway appurtenances, signalization, signage, marking, lighting, trees, and plantings, and may also include replacement of utility lines located within the road right-of-way.
Design of a lane placed in addition to and adjacent to a through lane, intended for a specific maneuver such as turning, merging, diverging, and weaving.
Design of a type of ramp or slip road where, instead of a standard left turn being made from the left lane, left-turning traffic uses a ramp on the right side of the road.
A highway pavement is a structure consisting of superimposed layers of processed materials above the natural soil sub-grade whose primary function is to distribute the applied vehicle loads to the sub-grade. A pavement design is the determination of the number, material composition, and thickness of the different layers within a pavement structure required to accommodate a given loading.
Design of a curb ramp that provides an accessible route that people with disabilities can use to safely transition from a roadway to a curbed sidewalk and vice versa. This ramp must conform to the standard Americans with Disabilities Act (ADA) specifications for ramps.
Modifications to a roadway to reduce traffic fatalities and serious injuries. Enhancements include centerline rumble strips, warning of curve ahead signs, cable median barriers, raised pavement markings, and roundabouts.
The design of the lighting system required to illuminate an interchange. Interchange lighting provides relative uniform lighting within the limits of the interchange, including main lanes, ramp terminals, frontage roads, or crossroad intersections.
Temporary erosion and sediment control is the practice of preventing or reducing the movement of sediment from a highway during construction through the implementation of man-made structures, land management techniques, or natural processes. These practices can consist of installing temporary linear sediment barriers; providing fiber rolls, gravel bag berms, or check dams to break up slope length or flow; or constructing a temporary desilting basin, sediment trap, or sediment basin.
A Driveway Permit Plan is a plan required by the Department of Transportation to obtain a permit to work within their right-of-way. Work that is typically done in the right-of-way includes adding or modifying an access point (driveway, new street, parking lot, etc.) or utility work.
Plans that depict the acquisition of an area of land, through dedication or easement, needed to accommodate the future widening of a roadway or a variety of other functions.
Stormwater management is the effort to reduce runoff of rainwater or melted snow from streets, lawns and other sites and the improvement of water quality. Best Management Practices (BMP) are used to protect water quality, enhance water availability, and reduce flooding potential.
Utility coordination involves identification and possible relocation of existing facilities that may be in conflict with proposed highway/bridge projects. Successful utility coordination requires early and frequent communication with utility owners, as well as cooperation and clear identification of the project scope and schedule.