Which Came First – Utilities or the Roadway?

When you’re looking at designing (or redesigning) a roadway, you need to think first about the impact that project will have on the utilities surrounding the road. If you don’t, you’ll likely find yourself grinding to a halt when you encounter a utilities-related roadblock in your next project.

Utilities are the lines, wires, and pipes that carry utility service to customers (either residential or commercial). Typical utilities you’ll encounter on roadway projects are power, telephone, cable, fiber optic, water, gas, and sanitary sewer.

Utilities can be a tricky component in your roadway design. Several utilities are located underground and are shown on surveys in an estimated location. The estimated location is obtained either by a utility locator spray painting a mark on top of the ground or by a review of the utility map.

Vertical locations are estimated based on typical depths (generally 24 to 36 inches) based on input from the owner of the utility. Since the utility locations are estimated, not exact, evaluating direct conflicts can sometimes be difficult. Therefore, due diligence with utility companies is recommended during the planning stage to assess whether a conflict exists, the cost of potential relocations, and the impact the relocation(s) will have on the overall project.

When we start the design of a roadway, we prepare a concept drawing of the horizontal and vertical components of the roadway and assess the possible utility conflicts. If a conflict is possible, we do more investigation into the size of utility, clearances required by the utility owner, and exact location of the utility. Potholing is the process of locating utilities through excavation. Potholing the utility or a subsurface utility exploration may be needed to aid in evaluating the exact location of the utilities.

Sain has had several projects in which the utilities in direct conflict have been large and relocation was not feasible. Sometimes, that means they are vaults or main transmission lines. In those instances, we may have to re-design the roadway and/or drainage to avoid a conflict.

Utility relocations can add additional time to the overall construction schedule, and they need to be planned in advance. It is highly important to know when the utility relocation will occur – before, during, or after the roadway construction. Scheduling the relocations is critical and can be a source of significant delay if not properly coordinated. If the relocation will occur during the roadway construction, it can still have impact to the project schedule. 

We have worked on projects where the utility relocation is worked into the sequencing of construction, where the grading and utility relocation must be coordinated together. This can mean a gap in the middle of the roadway grading activities. 

Utility relocations can be costly. If you are tasked with preparing estimates of cost for your roadway project, utility relocations should be considered as they can be significant cost adds to the overall construction cost. We have seen entire projects be dropped by the project sponsor because the cost of the utility relocations made the project unfeasible.

A good rule of thumb is to question how the utility relocation will be funded; either it’s paid by the utility owner or by the roadway sponsor. Several factors, such as type of funding, type of project, type of utility, etc. play into who funds the relocation.

Make sure you’re considering all the utilities located in and around your construction project, or you could find yourself stalled unexpectedly for several months and surprised by the cost to your clients.