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Avoiding Utility Relocations
V. Design Strategies and Alternatives
Different stages in the development of a highway project offer different opportunities for making decisions that can help avoid utility relocations. These stages are planning, design, and construction. The planning stage is started years ahead of actual construction and typically begins with the feasibility analysis of a project identified on a State’s transportation master plan. The planning stage can last several years and generally ends with approval of a preliminary ROW map and authorization to begin topographic and utility surveys for design. The design stage, consisting of plans, specifications, and estimates (PS&E), is commonly broken into percentage completion such as 30 percent, 60 percent, and 90 percent. As the various design milestones are reached, the options available for avoiding relocations become fewer. Once the PS&E reach 100 percent, it is assumed that all project information is complete, and the project is competitively bid for construction. Prior to beginning construction, the successful contractor is responsible to notify the local one-call provider to perform the last available utility verification before construction begins. The one-call system is not a fail-safe, however, and without prior communication and coordination effort and utility designation / locating effort, some unknown utility could still exist within the construction corridor. This has the potential to cause project delay and cost overruns, or serious injury or death to construction workers.
This section summarizes the various strategies and alternatives reported on the agency survey conducted by NCE. There are many different strategies and the choices are dependent both on the type of utility conflict and the timing of conflict discovery (planning, design, or construction stage).
V.1 PLANNING STRATEGIES
The most important planning strategy for avoiding of utility relocations on highway projects is to provide all affected utilities, both public and private, with advance notification of the proposed project. This occurs through the distribution of highway master plans, project preliminary design plans, and the regular communication among agencies and utilities.
Meetings. Many of the agencies surveyed for this manual send out annual and even quarterly updates of their 5- or 6-year plans to all the utilities within their jurisdiction. This gives the utility the opportunity to program upgrades or expansions to their facilities located within the proposed construction corridor in conjunction with the highway project, and to identify potential conflicts with existing major utilities. The discovery of a major utility conflict (large diameter interceptor or transmission mains, interstate electric lines or fiber optic cables) having a substantial economic impact to the project allows alternate highway routes to be explored prior to proceeding with preliminary design. Conflicts with minor utilities (small diameter distribution mains and service laterals) are expected, and would not generally alter a proposed highway route in the conceptual stage.
Regularly scheduled meetings are one means of coordinating the planning effort. However, one of the pitfalls of this practice is that there are often too many meetings within a given jurisdiction for a utility company to attend. The most effective method is for the State or municipality to distribute information regarding the master plan and other project issues so the utility can determine the most important projects, then dedicate the necessary staff for meetings and coordination. As individual project development progresses, and approval to proceed with design is obtained, project specific meetings between design staff from the agency and the utility should be implemented.
Utility Coordinating Councils. Many States have formed Utility Coordinating Councils (UCC) as a forum for discussion of master plans and general utility issues. The UCC comprises representatives from utilities, governmental agencies, contractors, excavators, and support companies who meet on a regularly scheduled basis to discuss mutual problems, work programs and planning. All states are encouraged to form a UCC to aid the communication and coordination process. Examples of a variety of State UCC organizations can be found at the following web sites: North Carolina (http://greensboro.ncocc.org), New Jersey (http://njua.org), Georgia (http://www.gucc.com), Arizona (http://www.ci.phoenix.az.us), Florida (http://www.fucc.
org), Oregon (http://www.oucc.net), Washington State (http://www.wucc.org).
One-Call Notification. As mentioned previously, use of the one-call system to mark utilities for planning and design purposes is not a standard practice. Liability issues aside, the data and markings provided through the one-call system meet the criteria of Level C at best. However, because of the nationwide mandate to “call before you dig,” the one-call system remains a required part of all projects’ damage prevention strategy.
Subsurface Utility Engineering. Whether the use of SUE (see Section III) is implemented in a project is up to the agency, and is evaluated case by case. Detailed utility information, if deemed necessary, should be provided to the designer with the topographic survey and no later than the 30% design stage. Although relocations may still be avoided at later phases of the design, using SUE early in the design process provides the greatest potential for eliminating problems and achieving the greatest savings related to utility conflicts. The following is taken from the FHWA’s “Program Guide: Relocations, Adjustments, and Accommodation on Federal Aid Highway Projects.”
Since 1991, The FHWA’s Office of Program Administration has been encouraging the use of SUE on Federal aid and direct Federal highway projects as an integral part of the preliminary engineering. Costs for SUE services are eligible for Federal participation.
Proper use of this cost-effective professional engineering service will eliminate many of the utility problems encountered on highway projects, including:
- Delays to projects caused by waiting for utility relocation work to be completed so highway construction can begin;
- Delays to projects caused by redesign when construction cannot follow the original design due to unexpected utility conflicts;
- Delays to contractors during highway construction caused by cutting, damaging, or discovering utility lines that were not known to be there;
- Claims by contractors for delays resulting from unexpected encounters with utilities; and
- Deaths, injuries, property damage, and releases of product into the environment caused by cutting utility lines that were not known to be there.
The application of SUE, by qualified providers who understand the process, makes it possible to avoid these problems. Unfortunately, some project owners and even some providers believe they understand the SUE process but actually do not and are, therefore, not realizing the maximum benefits. State agencies should no longer be relocating underground utilities unnecessarily or encountering them unexpectedly on Federal aid highway projects. The SUE technology is readily available to virtually eliminate these wasteful activities. Federal funds should not be used to participate in any unnecessary utility costs on projects where proven technologies, such as SUE, have not been used or have not been used properly.
Utility Agreements. A utility agreement is any document by which the highway authority regulates and/or gives approval for the use and occupancy of highway ROW by utility facilities. Utility agreements are based on the State’s utility accommodation policies and set forth the understandings, costs, and special considerations associated with a given project. When utilities already occupy (existing facilities), or request to occupy (new facilities), existing ROW, a permit is typically issued and represents the entire utility agreement. In the case of utility relocation, additional documents are normally required. A permit or agreement is a contract between the agency and the utility and is a permanent record indicating the utility’s right to occupy the ROW. The agency and utility are mutually bound to enforcing the requirements of the permits and agreements, ensuring that utility accommodation is a component of the project development and design process.
Some States have developed other agreements and/or test programs that give the State control of the positive locating process. In general, utility owners have been responsible for performing such positive locating activities as is necessary to provide agency designers with the location of their facilities within a project corridor. The agencies frequently require the positive location more expeditiously than the utility can readily or economically provide. In these cases, the positive locating agreement gives the State the authority to retain a contractor for potholing, or to retain a SUE provider to perform the entire locating process. These agreements cover all the utilities’ facilities within a given jurisdiction so that separate agreements for each project are not required. These agreements do not supplant the utility agreements / permits described in the preceding paragraph. A sample of a positive locating agreement can be found on the State of California Utilities Web Site at http://www.dot.ca.gov/hq/row/utility/.
Electronic Document Delivery. Although EDD is most important to the design and permit process of a project, it is also an effective planning tool. Highway planning data that can be electronically shared with utilities is an effective means to notify them of project status and/or meeting agendas. The State could be the party responsible for initial notifications providing an efficient means such as Project Wise, Groove, or other similar Web enabled document management systems were in place.
In support of EDD, there is great potential in also having a GIS that is accessible by all entities involved. New project data can be tracked through permit processes so that the information remains current. Appendix D contains a report developed by Texas Transportation Institute of a pilot GIS system being developed in cooperation with Texas Department of Transportation.
Cost Sharing. If a project redesign or alternate design to accommodate an existing utility would require a significant increase to the project design or construction costs, the utility is given the opportunity to pay for the increased project costs in lieu of an expensive relocation. In some cases the cost to the utility may be equal, but avoiding relocation has the advantage of no service interruptions. The DOT benefits also by not having to bear the additional project cost, or having to force the utility to relocate at their expense.
Joint Project Agreements. Many DOTs are advocating incorporation of utility work into the highway contract. Consolidating the work into a single contract improves the highway contractor’s control over the utility relocation and may result in lower costs. Although the Joint Project Agreement may contain provisions for dealing with relocation of unknown utilities encountered during construction, their primary purpose is to facilitate the relocation of utilities discovered in the design process, which were incorporated into the competitive bid package.
Context Sensitive Design. Highway projects involving disturbance of existing environmentally or community sensitive corridors have brought about the concept of Context Sensitive Design. Context Sensitive Design is a design approach in which agencies work with community stakeholders to develop a transportation facility that fits within the physical setting, and preserves community values and scenic, historic, and environmental resources, while maintaining safety and mobility.
Example: Overhead utilities typically include electric, telephone, cable television, and other communication lines. To preserve scenic corridors, new construction or relocation of these facilities often means going underground. Burying utility lines, although the safest and most aesthetically pleasing option, is also the most expensive. Often, undergrounding is not within the agency’s available budget. The challenge then becomes how to minimize the costs associated with the relocation and to design a relocation that will avoid the costs in the future.
The Maryland State Highway Administration has gotten very creative in trying to find cost-effective solutions that will still please the citizens. In lieu of undergrounding, they have used taller poles that are spaced farther apart, consolidating them to one side of the roadway, and or disguising them somehow to look like trees. By raising and consolidating the lines, much of the clutter is outside and above the driver’s and pedestrian’s views.
Locate Next to ROW. Because of clear zone issues, the FHWA requires above ground utilities be relocated as close to the ROW line as possible. This minimizes the potential for vehicular impacts. Most agencies require underground utilities to also locate as close to the ROW line as possible. This location has the least probable chance of conflict with widening of the highway.
Trenchless Technology. Under certain conditions, trenchless technology can reduce the costs of relocations. Trenchless technology encompasses a variety of methods to install, replace, renew, or repair underground facilities with minimal surface disruption by minimizing the surface open trench. Some of the methods of trenchless technology are utility tunneling, pipe jacking, micro-tunneling, pipe bursting, directional drilling, auger boring, and slip-lining. Although trenchless, the application of these technologies still requires the accurate locating of existing utilities in and around the work area and is therefore not a substitute for SUE services or one-call notification. A paper on Trenchless Technologies, presented by Mr. Terry McArthur, P.E, can be found on the AASHTO web site under the Highway Subcommittee on Right of Way and Utilities, Proceedings of the 2001 AASHTO/FHWA Right of Way and Utilities Conference, Chapter 4, http://www.transportaion.org/community/right_of_way/2001_cho4so1.pdf.
Joint Trenching / Utility Corridors. Some states relegate utilities to specific corridors or easements that will prevent them from coming into conflict in the future. Reduction in relocation costs and saving critical space in the ROW can also be accomplished by combining compatible utilities into a single common trench that has to be excavated and backfilled only once. As mentioned previously in this manual, however, constructors must be held to the design specifications for installing the joint trenches if utilities are to be expected to accept the additional liability with its use.
Utility Tunnels. No longitudinal utilities were allowed on freeway ROW until 1988 when the ROW was opened up to fiber optics and wireless towers. The telecommunication act opened up highway ROWs to hundreds of communications companies which has created tremendous problems. The use of utility tunnels has been proposed to alleviate some of these problems. This would involve constructing large diameter pipes or box culverts for exclusive utility use near the ROW in conjunction with the other highway construction. Using abandoned large diameter sewer and storm drain lines as tunnels for new, smaller diameter utilities is also a possibility.
Use of Subways for Dry Lines. In urban areas that have subway facilities, these corridors can provide space for “dry” lines such as fiber optics and other telecommunications.
Removal of Abandoned Lines. Out of service or abandoned utility lines within a project corridor can create major problems for agencies. Abandoned facilities are often undocumented and discovering who owns them and confirming their status can create costly delays. Utility lines that are in conflict and proposed to be relocated should be removed completely to avoid such confusion in the future. If for some reason portions of an abandoned line must be left in place, it should be documented on the as-built plans as part of the project record.
V.2 Design Strategies and Alternatives
The most effective way to avoid utility relocations is to have accurate and complete utility information in the hands of designers prior to any design activities taking place. In SUE terms, this means Quality Level B data within the 0 to 30 percent design phase. This provides the designer with the maximum flexibility in adjusting alignment and grade, or even obtaining more ROW in order to avoid costly, time-consuming relocations.
In reality, however, this is not usually the case. Conflicting utilities are often not discovered until well along in the design process and the geometric changes that could have eliminated utility conflicts are no longer possible. The cost or time required to do the redesign is too high, other alternatives must be sought.
In the Utility Relocation Survey conducted by NCE, most of the strategies for avoiding relocations during the design stage fell loosely into four groups: alignment and grade changes, drainage changes, structural changes, and slope / curb / retaining wall modifications.
V.2.1 Geometric and Alignment Changes
Changing the grade, or moving the alignment of the roadway is easiest in the planning stage or very early in the design stage (0 to 10 percent). As has been mentioned before, accurate information on the utility location is critical for effective changes to be made at this point. Even as early as 30 percent, there are so many design elements (cross streets, bridges, embankment balance) tied to the selected geometry and alignment that even with computer design systems, re-design is too time consuming to allow for changes. State agencies have stringent project delivery schedules that are driven by budget requirements, funding schedules, and tight construction seasons. So a grade or alignment change of just a few feet that could have saved hundreds of thousands of relocation dollars may not be approved because the delay in design could potentially delay the project an entire season.
Ideally, geometric changes would be made based on Quality Level B data and if grade changes are involved, that would mean some Level A data was collected on the depth of critical utilities as well. If that is not the case, then potentially high dollar decisions are being made based on data of unknown quality.
Case Example: A former Maryland Department of Transportation utility coordinator cites an example of a roadway project that included a bridge which conflicted with multiple utilities, power, water, sewer, etc. An adjustment of a degree or two in the alignment would have placed the bridge out of conflict with the power line with no adjustment to ROW or compromise in bridge function.
The design was complete and construction already well under way when the condition of the utility and the cost implications were discovered. The relocation costs were on the order of $5,000,000.
V.2.2 Drainage Changes
Storm drainage systems and runoff design can take the form of simple ditches tied closely to the geometry of the roadway or can be a fairly complex system of large pipes and inlets that can involve pumping stations in the most sophisticated applications. Transverse structures are those that carry water under the roadway, ranging from small corrugated pipes to box culverts to bridges. For large projects with sophisticated drainage systems, early, accurate information on utility locations is critical for designers to avoid potential utility conflicts.
The alternatives that are available later in the design (around 60 percent) become limited to the less expensive components of the design. Drop inlets, reverse throat inlets, pipe shape, ditch shape, changes from ditch to curb, encasement of the utility and pass through a conflict manhole, etc., may be used to avoid relocating utilities. If a conflict with a large utility and a major storm drain is discovered later in the design process, the re-design time may result in the utility being relocated instead of designed around.
V.2.3 Structural Changes
Structural changes included moving bridge bents and pilings, changing footing designs for piers or other structures or changing the bridge type altogether. Structural changes may also include the accommodation of a utility on the bridge structure by hanging the utility on the bridge, installing the utility in the deck or railing, or passing the utility through the bents. Changes to bridges, of course, need to be done as early as possible in the design process. Footings, and even pilings and piers in some cases, may be made later in the design process without too large an impact on the design schedule. One notable strategy involved pre-drilling pile casings. In this case, a boring is made past the utility, through the zone where the utility might have been damaged. The pile is then inserted in the hole and driven to bearing.
V.2.4 Slopes / Retaining Walls / Barriers
These strategies fall into the clear zone and safety issues that drive many design standards. Many agencies reported making alterations to the slope of the embankment or adding a retaining wall at the toe of the slope to prevent relocating utilities or avoiding encroachment over utilities. These solutions will generally require the addition of guiderails to compensate for the change in slope.
These alterations often occur in narrow ROW where the space required for a widening is limited, and, therefore, alteration to the standard geometry of the agency is warranted. Also included in this category is using barriers to protect above ground utility poles and other utility fixtures within the designated clear zone.
V.2.5 Other Design Strategies and Alternatives
Other strategies that were reported but did not fall into any of the other categories ranged from deleting the proposed design item altogether to increasing the mast arm length on signal standards. Since almost every conflict situation is unique, the potential for creative “out-of the-box” solutions is very high. Agencies with an institutional policy biased toward avoiding relocations will be rewarded with innovative solutions from their staff. The alternative is “we have never done it that way before” and “that is not my job” environments that will lead to continued unnecessary and costly relocations.
Selective Conflict. Selective conflict occurs when there are numerous utility conflicts within the ROW and the highway corridor. The design engineer then decides with which utilities does the conflict occur. A good decision again requires high quality data on the size and types of utilities involved, as well as the relocation costs involved. Other factors that would need to be considered in making this decision are not just relocation costs but user impacts as well. Taking a significant user offline may be a more significant impact on the community than the additional cost to move an alternative utility.
In another case, gravity lines and pressure lines occur in the same vicinity. In this case, the conflict should be directed toward the pressure lines which can be made to go around obstacles and are not affected by elevation changes. Gravity lines are limited in their adjustment possibilities because they are tied to manhole elevations and grade lines.
Case Example: All telephone lines are not alike. A Maryland designer wanted to relocate an overhead telephone line made up of 2700 pair cable. Fortunately, the utility coordinator informed them that the cable would need to be spliced by hand every 120 feet (30 meters) and each splice would require 10 days, delaying the project by 3 months.
Specifications. In some cases, the actual specifications under which a roadway is being constructed may be modified for an overall project benefit. Specifications that are designed with the intention of eliciting the best product in terms of pavement or bridge performance, for example, may not be the most cost-effective when their effect on utility relocation is taken into account.
Altering agency standard or project specifications is not something done lightly. Therefore, the cost or delay to relocate a utility would have to be significant for this option to be used. It should be kept in mind that specifications are not inviolate. They are created through a combination of research, national standards, tradition, past practice, and compromise. They are almost always conservative in order to take into account the construction and material variability inherent in the construction process. A valid way to justify adjusting specifications, then, is to provide assurance that the highest quality materials and workmanship are being used through increased testing or inspections. A thinner pavement section may be allowed if it can be shown that asphalt concrete (AC) contents and gradations are tight and uniform, or a shallower footing provides adequate structural support because the concrete strength is significantly higher than originally required.
Case Example: On the I-15 project through Salt Lake City, the specifications called for a 36-inch (900-mm) structural pavement section to mitigate potential frost damage. This meant that material below the pavement surface had to be granular material down to 36 inches. This was not a problem on the mainline and ramps where the embankment was being built up, but in one industrial area where the local roads were being reconstructed, that depth brought many existing utilities into conflict with the proposed cross section. Approximately 24 inches of material would have had to be over-excavated out and replaced with select fill and this over-excavation would also have run into numerous utilities.
The Corps of Engineers frost depth chart showed potential frost depths were only on the order of 20 inches in this area. The 36-inch frost specification that was intended to help insure 40 years of excellent performance on mainline interstate pavement was being applied to local streets with a 20-year design life. This would provide little in the way of added benefit, and would drastically increase the cost and delay associated with this portion of the project.
A significant amount of negotiation between the Design/Build contractor and the owner was required to reach an agreement. Ultimately, a reduced pavement section was allowed that met the climatic requirements for the location, the performance intent of the specifications, and eliminated the need for an undetermined amount of utility relocations by bringing the bottom of the pavement section up out of the utility zone.
Materials. Material selection is another method for reducing or altering a pavement section so that a utility relocation is unnecessary. Stronger, lighter, or higher quality materials than those typically called for can result in thinner pavement sections and reduced embankment loads that would otherwise force relocation. Using pavement layers with higher layer coefficients such as bound bases using asphalt, lime, flyash, or portland cement can shave inches off pavement structural sections. This can provide the needed clearance over the top of utility lines where the final grade is constrained. Using higher strength concrete can also reduce portland cement concrete (PCC) pavement sections or the thickness or depths of other concrete structural components.
The trade-off with material selection is that better materials cost more and, therefore, must result in time or money savings overall to be justified.
Case Example: The I-15 project through Salt Lake City was a major reconstruction of an urban interstate freeway. Capacity improvements required an increase in width from 6 lanes to 12 lanes typically, and sometimes 14. This resulted in large amounts of fill to raise embankments to accommodate the roadway widths as well as three major interchanges. These fills were often on the order of 50 or 60 feet in height. One of the major design challenges faced by this project was accommodating the large settlements of the soft lakebed soils underlying the project due to these large fills.
In one area, a number of utilities were located below a large increase in embankment for an interchange. The utilities consisted of water and gas mains so the relocation costs and associated delay were huge. The problem was that the potential settlement due to consolidation of the underlying soils was several feet. In other areas, surcharge fills were used to get the consolidation out of the soils prior to final construction but in this case any consolidation would damage the existing utilities.
To avoid relocation, a lightweight geofoam embankment was used. This consisted of big blocks of dense styrofoam stacked in a triangular cross section and covered with fill and a thin cap of concrete over the utility area. Some of the existing fill was actually removed so there was no net increase in load over the utilities. This eliminated any future consolidation that could have ruptured the water and gas mains.
Other types of lightweight fills exist that can significantly reduce the loading on underlying soils.
Standard Drawings for Conflict Resolution. Several agencies have suggested that as utility conflicts become more and more common, there is a potential for developing standard drawings that would deal with the most common types of conflict situations. That would help prevent the process from being put on hold while a solution is sought. It would also create an atmosphere within the agency that promotes avoiding relocations as a valuable and desirable result of the design process.
There are no case examples for this strategy but potential items that may fit well into a standard drawing detail are retaining walls or gravity walls at the edge of a slope to keep from getting into utility easements. Storm drain inlets that are modified to avoid utilities at the edge of the pavement are also good candidates.
Cast-in-Place vs. Pre-cast. Many agencies are using more and more pre-cast concrete products for drainage and other structures to the extent that if the pre-cast section will not fit around a utility, the utility must be moved to accommodate the pre-cast unit. Concrete structures can still be cast-in-place and formed around some utilities without compromising performance of either the structure or the utility.
Adequate ROW Acquisition. In some cases, the utility information is limited early in the scoping process. This has on occasion lead to a situation where a utility had to be relocated because not enough ROW was acquired to accommodate both the roadway and the utility. Depending on the specific site conditions, the acquisition of ROW may be less expensive than a utility relocation.
Case Example: A case has been reported where a foot of ROW would have been sufficient to avoid a major relocation but the need was not apparent during the ROW acquisition process. This is again a situation where having good SUE information very early in the process is necessary for good decisions to be made.
Insulating Covers for Water Lines in Cold Climates. In cold climates such as Alaska, insulating covers have been used to reduce the amount of cover require for water lines.
V.3 Summary of Relocation Strategies
Following is a summary list of the design strategies and alternatives that were reported by agencies responding to the NCE survey. They are listed here as reported, but have been broken into the categories previously described.
Geometric / Alignment Changes
- Widen one side of highway as opposed to other
- Offset location of centerline for short distances
- Move ramps
Drainage / Ditch / Culvert / Inlet / Curb Changes
- Move storm drains
- Low head storm pipe
- Alternative type inlets
- Alternative storm drain (oval, etc.)
- Ditch culverts
- Narrow ditch widths
- Redesign ditches from flat bottom to “V” bottom
- Adjust flow lines
- Ditch grade changes
- Use paved ditches
- Change from ditch cross section to gutter
- Adjust manhole locations
- Extend storm pipe runs to avoid ditch cuts that impact utilities
- Concrete slabs over utilities in ditch bottom
- Revise or eliminate portions of the drainage design
- Install closed drainage and curbing
- Use rip-rap on ditches
- Add curb and gutter
- Alternative curb and gutter
- Reverse throat drainage structures
- Install a manhole at the conflicting location, encase the utility and pass it through.
Slope / Retaining Wall/Barrier Changes and Additions
- Guard rails instead of moving poles
- Change backslope rate
- Add retaining walls to the design to reduce slope encroachment
- Remove slope rounding
- Change retaining wall types
- Impact attenuators on above ground appurtenances
Structure / Bridge / Footing Changes
- Move bridge bents
- Move bridge end that would conflict with pipeline
- Alternative foundations
- Move bridge ends
- Structural box modifications
- Structure footing redesign
- Abutment modifications to allow bridge occupancy
- Customized foundation design
- Move bridge pilings
- Change bridge type
- Use protective casings
- Pre-bore and batter pile driving to miss utilities
- Hang utilities on the bridge, install the utilities in the deck or railings, or pass under the deck through bents.
Other Relocation Avoidance Strategies
- Insulation over water pipe (AK)
- Concrete over electric
- Approved nonstandard design changes
- ROW reduction to avoid utilities (LA)
- Signal standard changes
- Increase mast arm lengths
- Move proposed signal or sign locations
- Require hand digging or trench boxes as a design plan note
- Delete proposed design item altogether
- Protective shielding (reventment material)
- Move field entrances
- Adjust sidewalk alignment
- Revise detours
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