A successful PS&E project relies on a thoroughly designed schematic

For more than a decade, I’ve led roadway design on schematic and plan, specification, and estimate (PS&E) projects in Texas. I’ve seen the benefits of a well-designed schematic, and I’ve seen the issues that result during PS&E from a concept-level schematic.

A successful schematic starts with identifying project-specific challenges and collecting data to assess and resolve them. To achieve a 30% PS&E design level at the schematic stage, key elements I focus on include adequate right of way (ROW), ultimate roadway footprint, design exceptions and waivers, and proactive utility planning. Attention to these commonly overlooked factors results in a quality schematic setting up the PS&E phase for success and keeping projects on schedule.  

Establish a comprehensive ROW footprint

Once PS&E is underway, obtaining additional ROW outside a set footprint is time consuming and costly. It is critical to establish ROW limits during schematics by collaborating with all disciplines and identifying key design challenges surrounding current and future needs based on roadway classification and projected traffic volumes. It’s also important to develop a fully vetted 3D model that includes detailed grading for interchanges and areas with large variations in the natural terrain; uses clash detection for sight design checks at intersections to establish corner clips; accommodates areas for roadside drainage, detention and water quality systems where necessary; and does not impede utilities.  

Using the 3D model, section cuts can be reviewed by subject matter experts to identify any fatal flaws in the ROW footprint and confirm adequate ROW is acquired prior to beginning the PS&E process or, at minimum, prior to construction. Environmental impacts are additional factors to consider when setting the ROW footprint, as well as incorporating cost analysis to compare ROW acquisition cost vs. cost of retaining walls or other measures to reduce the grading footprint.  

Take future development into consideration

Comprehensive schematic design can only be achieved when taking future developments into consideration. Coordination between the client, consultants, other agencies, and ongoing or future adjacent projects is critical to account for all planned development and land use. By using existing traffic counts and collected future development data, future traffic volumes can be projected, and teams can perform traffic modeling to establish a level of service and help determine the ultimate roadway needs and footprint.

Recently, my team and I completed the schematic design for I-35 Northeast Expansion (I-35 NEX) project in San Antonio, which encompasses over 40 miles of elevated roadway and is set to open to traffic in 2027. During the schematic design for I-35 NEX, we worked with our client to analyze all intersections throughout the corridor, allowing my team and I to confirm the proposed column placement for the elevated lanes didn’t prevent future intersection improvements or expansion. 

Identify design exceptions and waivers early

Identifying locations where exceptions and waivers are required is a critical step in the schematic phase to streamline the PS&E process. Checks of the schematic design against the design manuals provided by your state’s department of transportation (DOT) or governing agency should be conducted at every milestone or significant design change to confirm the schematic meets criteria.

Design exceptions are sometimes unavoidable and must be identified early in the project development process. On a recent schematic design, we encountered the need for a design exception due to significant environmental constraints: a cemetery bordered one side of the roadway, while a railroad corridor constrained the other. These fixed boundaries prevented any outward expansion of the roadway footprint, making it impossible to achieve the minimum required shoulder width.

Identifying design exception/waiver and obtaining approvals during the schematic phase helps prevent unexpected delays during PS&E development. Early approval confirms that geometric constraints are resolved before detailed design, reducing the risk of impacts to the project schedule and protecting letting dates. It is also vital that teams keep pedestrian and commuter safety in mind when identifying project-specific design exception needs. 

Plan proactively for existing utilities

Utilities must be considered at every stage of design. During the schematic phase, the focus should extend beyond identifying approximate utility alignments to obtaining Quality Level A and B subsurface utility engineering (SUE) in areas where conflicts are anticipated or already evident — particularly when utility relocations may become critical‑path or long‑lead items during PS&E.  

Early identification of existing utilities not only helps mitigate conflicts but also prompts the design team to plan appropriately for the placement of relocated and proposed utilities within the project footprint. Large‑capacity transmission lines are a prime example, requiring significant coordination and planning for utility adjustments. Teams should also prepare for planned utility developments and reflect them accordingly in schematic designs prior to PS&E.  

A strong schematic produces a smooth PS&E process

A successful PS&E project begins with a well-defined, fully vetted schematic. By establishing an accurate ROW footprint, anticipating future development, identifying design exceptions early, and proactively planning for utility conflicts, teams can reduce risk, avoid costly redesigns, and maintain project momentum. These focus points not only strengthen the quality of the schematic but also facilitate a smoother PS&E process, ultimately helping projects deliver on time and within budget.