Engineering in TPDP includes the core processes by which MnDOT plans, develops, designs, and constructs transportation projects, then operates and maintains the resulting transportation facilities. Engagement and environmental processes are integral to each step in the engineering process. For clarity, TPDP shows engagement and environment as parallel lanes in the process diagram and treats each in its own section of TPDP.
Planning involves stakeholder engagement processes and analysis to develop goals for the transportation system and plans to achieve those goals. These efforts culminate in identifying projects to improve the transportation system. Broadly, the planning process progressively narrows the focus from transportation system-level to project-level through these steps:
- Identify transportation system goals, objectives, performance measures, strategies and investment priorities
- Identify a realistic vision for the corridor that is consistent with state, regional and local plans
- Identify and document high-level problems and opportunities through one (or more) of the following paths:
- Planning studies – including corridor, regional, MPO, and other studies
- Asset management reviews – including the project selection process
- Standalone issues
- Document specific problems and opportunities for a segment of the transportation system
Scoping is the process of developing the project scope. It begins when a transportation need is identified and management decides to invest resources in addressing the need. Scoping is a stakeholder engagement activity that involves gathering engineering and environmental data and public input, analyzing the information, and following a decision making process to determine the scope of the project. It is complete when a preferred alternative has been identified and the construction work necessary to meet the project objectives has been defined and documented.
Preliminary design establishes how the project will meet the objectives identified in the scope. Typical products of preliminary design include a staff-approved geometric layout and design memo; however, the products of preliminary design vary depending on the project type.
Final design takes the concept and parameters established in preliminary design and develops them into a detailed design, culminating in the construction plan set, designer’s cost estimate, and special provisions.
Construction includes the physical and administrative processes of building the transportation facility specified in the plans. The project manager must keep the construction process in mind during project development to ensure the project can be constructed safely and efficiently, while minimizing impacts to communities, natural resources, and cultural resources.
Operations and maintenance is the phase when the facility is open to travelers. During this phase, MnDOT monitors and optimizes facility performance and addresses condition issues. Throughout project development, the project manager must make decisions that will support safe and efficient operation and maintenance of the transportation facility.