palm trees line the road

Project Resources

blue video icon


How are projects identified, and how do we pick the right solutions?

Right of Way Video
Overview: Environmental Study Process for SCDOT Projects
Infrastructure and Hydrology

Assessing and Measuring Noise Impact of New Road Projects

Overview: SCDOT Project Development Process

2016 Virtual Public Meeting (Archive)
blue meeting resources icon


View the I-526 LCC WEST Reasonable Alternatives Maps

*Download on a desktop for full functionality.

Click through to an interactive map of the I-526 Lowcountry Corridor WEST Project Area.

Click through to an interactive map of the Berkeley-Charleston-Dorchester County transportation improvement projects.
blue newsletter icon



Generally speaking, capacity refers to the maximum amount something can contain. Similarly, capacity, when referring to transportation, is a measure of how much traffic a given transportation facility can accommodate.


Transportation Corridors are typically a linear area with one or more modes of transportation, such as highways, railroads, or public transit, linking major gateways and hubs, where both passenger and freight traffic mix.


The traditional project delivery method that SCDOT has historically utilized to deliver transportation projects. SCDOT performs design and develops all the construction plans and documents and therefore, serves as the engineer-of-record and bears the majority of the design risk. Once design has been completed, the project is let for construction. A single contract is awarded to provide construction services. Design-bid-build projects often utilize unit price contracting methods, but other methods may be used. More here.


An alternative project delivery method in which a single contract is awarded to provide both design and construction services. In this method of project delivery, contractors and consultant design firms form an integrated team and assume the responsibility for design and construction. Any design errors or omissions discovered during construction and the warranty term are the responsibility of the Design-Build Team to correct, thus transferring any design risk to the Design-Build Team. Design-build projects are typically lump sum contracts. More here.

Draft Environmental Impact Statement

See Environmental Impact Statement

Environmental Assessment (EA)

TA concise public document for which a Federal agency is responsible that serves to (40 CFR 1508.9):

  • Briefly provide sufficient evidence and analysis for determining whether to prepare an environmental impact statement or a finding of no significant impact.
  • Aid an agency’s compliance with the Act when no environmental impact statement is necessary.
  • Facilitate preparation of a statement when one is necessary. Shall include brief discussions of the need for the proposal, of alternatives as required by section 102(2)(E), of the environmental impacts of the proposed action and alternatives, and a listing of agencies and persons consulted .
Environmental Impact Statement

NEPA requires Federal agencies to prepare environmental impact statements (EISs) for major Federal actions that significantly affect the quality of the human environment. An EIS is a full disclosure document that details the process through which a transportation project was developed, includes consideration of a range of reasonable alternatives, analyzes the potential impacts resulting from the alternatives, and demonstrates compliance with other applicable environmental laws and executive orders. The EIS process in completed in the following ordered steps: Notice of Intent (NOI), draft EIS, final EIS, and record of decision (ROD). More here.

Facility (Transportation Facility)

Used to describe a road, street, bridge, parking area, transit vehicle or other related transportation infrastructure.


To make better. When related to transportation, an improvement could be some sort of action that provides relief from congestion, improves safety, or provides some other benefit over the current situation.


An intersection describes two roads that cross at the same level, like typically found at a stoplight. An interchange is similar in that it is an intersection that is grade-separated, meaning one road passes over another with ramps to connect them. Factors such as safety, cost, capacity, the environment, and more vary from site to site. Interchanges are designed to fit specific local conditions. There are various types of interchanges which are typically named for the shape of the roads, such as a “cloverleaf” or “diamond” interchange.

Level of Service

Related to Capacity, Level of Service (LOS) tries to answer how good is the present traffic situation on a given facility. While capacity is a quantitative measure, LOS is a qualitative measure.


Mobility refers to the ability and level of ease of moving people or goods.

Peak Hour

Refers to the busiest hour(s) of traffic; the part of the day in which traffic congestion is the highest.

Purpose and Need

The Purpose and Need is one of the most important sections of an Environmental Impact Statement (EIS) for a project. The purpose and need drives the development of the range of alternatives. Some of the common needs include transportation demand, safety, legislative direction, urban transportation plan consistency, modal interrelationships, system linkage, and the condition of an existing facility.


Used to either access or leave a highway or interstate.

Study Area

The project study area is the area in which field data is collected to identify all known environmental resources (human or natural). Established early in the process, this area must be large enough to house all potential project alternatives.