Utility Location and Highway Design (2010)

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27 A subsurface utility engineering mapping effort addresses many issues that directly affect the quality and comprehensive- ness of utility mapping that One-Call responses are not equipped to address. The One-Call system is only a messaging service, routing a request from a designer or excavator to a utility owner. In turn, that utility owner sends out a person to mark the utilities within the project limits described on the request. As such, if there are ten different utility owners within a project limit, there may be ten persons in the field marking those individual utilities. Sometimes utility owners contract these marking services to other firms; sometimes more than one utility owner in an area contracts with the same utility marking firm, although this prac- tice once common is becoming more rare. Not a single One-Call statute in the country requires abandoned utilities to be marked, although this is more of a construction issue than a design one. Regardless of whether utility owners should mark during design, here are some arguments as to why they cannot do a job as well as a single entity responsible to mark all utilities on a project. The very nature of a single entity (say for instance a subsurface utility engineer) marking all utilities within the project limits fos- ters an environment where utilities can be marked on the ground surface with greater reliability than during One-Call operations. For convenience sake, we will call the marking of utilities by a subsurface utility engineer as “designating” and by a utility owner or One-Call locator as “locating.” Consider these typical comparisons: Designator: Possesses all utility owner records Locator: Possesses only those records for the utility owner for which he/she is under contract. Designator: Finds and marks all utilities Locator: Only marks some utilities—does not have advantage of seeing all parts of the puzzle. For instance, aban- doned utilities, unknown utilities, multiple non- encased wires, etc., cause identification confusion. Designator: Has realistic time constraint for finding and marking utilities Locator: Is under severe time constraints for getting utilities marked. Designator: Has many pieces of equipment on-site or readily available Locator: Has limited equipment available. Designator: Maps large area, allowing better familiarization with utilities at site Locator: Usually only responsible for a very small area at any given time, making it difficult to see the large picture. Designator: Because of large area to be marked and no time con- straints, traffic control can be set up, allowing time and security for decision and precision. Usually has at minimum a two-person crew Locator: Usually no time for traffic control. Runs between vehicles when safe. Usually a one-person operation; almost never is there more than one person on-site. Designator: Opens and inspects all available utility structures and addresses each utility wire and conduit source to source Locator: Typically is not allowed to open any utility struc- ture, therefore not getting the best possible data on number of cables or conduits or having ability for direct signal application. Designator: Can place transmitter over utilities in traffic Locator: Cannot use equipment effectively in traffic owing to one-person limitation. An additional and significant problem exists when utility owners mark their utilities. Someone has to transfer that data from the ground to the Computer Assisted Design and Drafting file. This process begins with the surveyor. However, when the surveyor has no control over the process of the field marks, he does not know when to go survey the marks. He does not know if all the marks have been made in the field. He may need to make multiple trips to the same spot to survey additional marks. Forty percent (40%) of DOTs report that they use their survey forces, and/or their outside design consultants do, in this man- ner. This results in inefficiencies and potential quality issues. These issues become moot when the entities making the marks and the surveyor of the marks are the same responsible party. APPENDIX A Subsurface Utility Engineering versus One-Call