Transportation & Structure Design

The SEA Transportation & Structure Design Group is comprised of seasoned professionals experienced with the design and rehabilitation of bridges, culverts, and retaining walls throughout the southeast.  Bridge types vary from small stream crossings to large multi-span bridges. Our team has designed bridges on tangent and curved alignments utilizing superstructures that include cored slabs, prestressed concrete girders, steel rolled shapes, and steel plate girders.  Our extensive experience and knowledge allows us to design and deliver highly functional, cost effective, and aesthetically pleasing designs for our clients.

Specific services include:

  • Bridges (Superstructure, Substructure, and Foundation)
  • Reinforced Concrete Box Culverts
  • Reinforced Concrete Retaining Walls
  • Microstation Drawing Platform

In-Service Bridge Inspection

The SEA In-Service Bridge Inspection Group is comprised of seasoned professionals with extensive experience providing safety inspections of in-service bridges for state and municipal governments as well as privately-owned bridges and structures.  All inspections are performed in accordance with the National Bridge Inspection Standards (NBIS) by inspectors who have been certified by the Federal Highway Administration (FHWA) and the National Highway Institute (NHI).  Our team has inspection experience with several types of bridges, including prestressed concrete girder, reinforced concrete girder, prestressed concrete cored slab, concrete deck slab, concrete segmental box, steel truss, timber beam, and steel beam.  Other structures inspected by the SEA team include reinforced concrete box culverts, corrugated metal pipes, reinforced concrete retaining walls, metal high mast light poles, and metal traffic signal poles.  We also perform bridge load ratings in order to assess the safe load capacity of a bridge to determine if a posting is necessary.

Specific services include:

  • Safety Inspection
  • Operational and Inventory Bridge Rating

Environmental / Planning Services

The SEA Environmental / Planning Group is comprised of seasoned professionals with extensive experience in Transportation Project Planning, Project Management, Environmental Compliance, Public Involvement, and Community Studies.  Our team has authored and managed both NEPA and SEPA projects, ranging from complex federal Environmental Impact Statements to straight-forward state Minimum Criteria Determination Checklists.  Along with project development documentation, we specialize in Community Impact Analysis, Indirect and Cumulative Effects Determinations, and Land Use Screening Analysis.  We have planning experience that covers a range of transportation modes from small to large roadway improvements, railroad upgrades and crossing closures, transit feasibility and ridership surveys, pedestrian and bicycle accommodations, and airport enhancements.  Our collaborative and attentive approach to project planning enables us to identify potential problems and recommend solutions early in the project planning process, allowing project schedules to be maintained.

Specific services include:

Environmental Planning

  • Categorical Exclusions
  • Community Impact Assessments
  • Ecological & Biotic Studies
  • Environmental Assessments
  • Environmental Impact Statements
  • Minimum Criteria Determination Checklists
  • Environmental Justice
  • Indirect and Cumulative Effects
  • Section 4 (f) Determination
  • Section 6 (f) LWCF Compliance
  • T&E Species Surveys and Studies
  • Section 7 ESA Consultation
  • Wetland and Stream Delineation

Public Involvement and Communications

  • Community/Stakeholder Involvement
  • Project Communications
  • Stakeholder Identification/Management
  • Strategic Planning
  • Writing/Editing

Construction Observation

Since 2010, Simpson Engineers & Associates (SEA) has provided Construction Project Management Services to the NCDOT – Rail Division.  SEA employees utilize years of construction project experience in order to review construction activities and report progress to NCDOT Management, City Officials, FRA Officials, and Railroads.  Our project managers are responsible for providing RFI submittal and review, while coordinating with NCDOT, Railroads, and the Designer of Record, in order to successfully deliver a combined response to the contractor.   Our services begin with pre-construction plan review and cost estimates, continue through identifying and developing ways to address constructability, advising on delay issues, and finish with reporting on the progress of a project through completion.

Specific services include:

  • Construction Oversight
  • Construction Compliance Document
  • Subgrade Stone Density Testing
  • Asphalt Density Testing
  • Nuclear Density Testing
  • Conventional Density Testing
  • Field Inspection and Testing Services

NCDOT Rail Division Project Management

Since 2009, SEA has established a multidisciplinary team of experienced professionals dedicated to providing quality service to NCDOT – Rail Division. We integrate engineers and other specialists seamlessly to provide an experienced team with proven performance on NCDOT projects.  We have selected the industry’s best to be on our team and have excellent working relationships with all of our clients.

We are continuously seeking and employing cutting-edge methods and technology to accomplish tasks with increased accuracy and efficiency.  We stay abreast of the most recent guidelines and innovations in order to effectively provide NCDOT with current and accurate project development.

Specific services include:

  • Construction Administration
  • Demand Modeling, Ridership, Revenue, Project Planning
  • Historic Passenger Station Renovations
  • Maintenance Facilities
  • Passenger Platforms
  • Passenger Station Design
  • Rail Construction Project Inspection and Management
  • Rail Corridor Maintenance Assessments, Surveys, and Lease Studies
  • Rail Corridor Traffic Modeling and Capacity
  • Rail Facilities
  • Rail Functional and Preliminary Design, Project Planning
  • Rail Sidings
  • Railroad Communications and Signal System Design
  • Railroad Crossing Signal and Traffic Engineering Services
  • Review of Engineering Drawings, Standards and Specifications
  • Studies of Economic and Fiscal Impact of Rail Related Activities
  • Technical and Negotiation Assistance in Securing Rail Lines and Corridors
  • Traffic Separation Studies and Crossing Evaluation Studies
  • Train Performance and Rail Line Capacity Analysis
  • Viability Analysis and Support Work for Railroad Related Projects