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Systematic Approach for Determining Construction Contract Time: A Guidebook (2022)

Chapter: Chapter 4 - CTD Guide for APDMs

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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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Suggested Citation:"Chapter 4 - CTD Guide for APDMs." National Academies of Sciences, Engineering, and Medicine. 2022. Systematic Approach for Determining Construction Contract Time: A Guidebook. Washington, DC: The National Academies Press. doi: 10.17226/26537.
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63   APDMs dier from the sequential DBB delivery approach, which is typically paired with a low-bid procurement method. Although APDM projects constitute less than 5 percent of the total number of projects let by a typical DOT, they can represent as much as 30 percent of a DOT’s annual budget because they tend to be reserved for large projects (Antoine et al. 2019). Given the variance in legislative, regulatory, and policy constraints governing the letting of APDM projects among the states; the relatively limited amount of CTD data; and the uneven- ness of APDM implementation across DOTs, the research team used interviews and case studies to synthesize generally applicable approaches for CTD in APDM projects. APDMs have proliferated over the last 2 decades as an eective response to rapidly renew the nation’s deteriorating infrastructure. DB, CMGC or CMR, and P3 contracts take advan- tage of construction-centric innovations to improve cost and schedule certainty and provide novel solutions for dicult, complex projects. e FHWA Every Day Counts program identi- ed APDMs as a means of “shortening project delivery, enhancing the safety of our roadways, and protecting the environment” (Mendez 2010). Research has consistently demonstrated that owners turn to alternate project delivery methods when they need to accelerate the delivery of critical transportation projects (FHWA 2006, Gransberg and Molenaar 2019, Lopez el Puerto et al. 2017, Scott et al. 2006, Songer and Molenaar 1996). For most projects, the determination of contract time is a key issue in deciding whether APDM is a viable option. e next section briey reviews three major APDMs in relation to both the context of estimating the construction schedule and determining the impact of the APDM on the CTD. From a CTD standpoint, the DB portion of P3 projects is the period of interest. us, the system used to adjust DB CTDs will be directly applicable to P3 projects. Figure 4-1 diagrams the three APDM timelines alongside a DBB timeline. e gure illustrates the approach that will be used to adjust DBB CTD periods for CMGC, DB, and P3 projects. 4.1 Generic APDM CTD Framework e proposed APDM CTD framework is based on the fundamental assumption that the duration of construction activities will essentially parallel the duration estimated for a DBB project. erefore, the dierence between APDM CTD and DBB CTD is the period needed to conduct the necessary design to permit the rst construction work package to be released for construction. is period is called the preconstruction period. It is important to understand that this period is NOT the amount of time it takes to complete the nal design. e duration of the preconstruction period is a direct function of how far the DOT has advanced the project’s design before issuing a request for proposal (RFP). e literature has shown that no standard exists for level of design shown in the RFP. RFPs for past projects have C H A P T E R   4 CTD Guide for APDMs

64 Systematic Approach for Determining Construction Contract Time: A Guidebook ranged from almost no design to nearly 90 percent design. Given that accurately quantifying the preconstruction contract time is highly project dependent, it is virtually impossible to empiri- cally derive a generic methodology. Consequently, the proposed framework seeks to bound the uncertainty and furnish a range of estimated preconstruction times that can be used to better inform the nal CTD decision. e APDM CTD framework involves relating information from ve domains to make the nal determination. e ve domains are: 1. Time constraints on funding, 2. Agency procurement timeframes, 3. Urgency of project completion, 4. Technical constraints on design and construction, and 5. External constraints on construction progress. Notably, the rst four domains are not independent, which means an iterative process must be used to optimize the timeframes that will inuence the nal contract time. Once that process ACM Project Delivery Timelines De sig n- Bi d- Bu ild Co ns tr uc tio n M an ag er / Ge ne ra lC on tr ac to r De sig n- Bu ild Pu bl ic Pr iv at e Pa rt ne rs hi p Project Delivery Period Design PreconRFQ/RFP Award Build Design Advertise/Bid Award Build CTD Design BuildPreconRFP Award CTD CTD Design Precon Operate/MaintainRFQ/RFP Award Build CTD CMGC-CTD = DBB-CTD DB-CTD = P3-CTD Figure 4-1. APDM project delivery timelines in comparison to DBB timeline.

CTD Guide for APDMs 65   is complete, the external constraints must be imposed before the nal contract time can be estab- lished for the APDM project. Figure 4-2 represents the proposed framework graphically and places the ve domains in two categories: domains that are controlled internally and domains that come from external factors. e framework can be implemented by using one or more tools to estimate the duration of the allowable preconstruction period and relate it to the allowable construction period to develop a complete no later than date that can be articulated in the APDM solicitation. e agency can use that date as part of its evaluation plan and encourage early completion by rewarding propos- als accordingly rather than issuing monetary incentives. Nevertheless, whether early completion is incentivized is immaterial to the setting of the required contract completion date. 4.2 Overlap Between Design and Construction Activities Reduced project delivery time on APDM projects is primarily achieved by overlapping design and construction activities. Construction activities can commence before the project has reached a 100 percent design; however, it is important to realize that this statement only holds true when it refers to the entire project. For example, when looking at a typical DB project, the construction ACM CTD Framework In te rn al CT D Fa ct or s Ex te rn al CT D Fa ct or s ACM Contract Time Determination Agency Procurement Timeframes • Certification of funds • Review of procurement documents • Approval to advertise • Mandatory advertising period • Etc. Funding Time Constraints • Federal funding issues • State funding issues • Fiscal year issues • Expiration dates • Bond timeframes • Etc. Urgency of Completion • Structural deficiency • Inadequate capacity • Maintenance of traffic • Seasonal impacts • Etc. External Constraints • Political commitments • Public involvement • Major events schedule • Elections • Legislative schedule • Etc. Technical Constraints • Scope development • Approval of design approach • Preliminary Engineering • Cost estimating issues • Etc. Final Funding Time Final Urgency Time Final Technical Time Final Agency Procurement Time Final External Time Figure 4-2. APDM CTD conceptual framework.

66 Systematic Approach for Determining Construction Contract Time: A Guidebook of the rst work package can begin before the overall design is complete (see Figure 4-3). at said, the necessary design for the initial work package must be suciently advanced that all design documents associated with that particular work item have been certied and approved for construction purposes. is process, termed released for construction (RFC), is described in detail in typical DB contracts. e key to achieving concurrency between design and construction activities while maintaining the RFC design requirement before construction is to break down the entire project into multiple smaller phases/packages/buildable units using a procedure called work packaging. Deciding what to include in each work package largely depends on the characteristics or salient features of individual projects. For highway projects that have signicant phasing plans, each phase in the trac phasing plan may be considered as a distinct work package. Alternatively, the work package may be based on the physical location of the project. For example, a highway interchange project can be broken down into four work packages by dividing the entire project into four main quadrants (e.g., a northeast quadrant, southeast quadrant, southwest quadrant, and northwest quadrant). An agency also may choose to divide the work packages of a project based on the readiness of each road section. e readiness of a road section may be assessed in terms of ROW availability and/or the amount of engineering/design work needed to reach a status called issued for construction. If a road section has been identied as being able to proceed into construc- tion sooner than other sections, treating it as a separate work package allows the construction team to commence work on it while the design team continues working on the other sections. A universally correct way of developing work packages does not exist. Thoughtful work packaging will allow both the agency and the contractor to utilize their resources more e- ciently and eectively. When planning each work package, it is also important to consider that some on-site work activities may be permitted to be performed before the design of the specic work package is nished. ese early work activities include but are not limited to clearing and grubbing, rough grading that involves a substantial amount of earthwork, and construction of Figure 4-3. Work packaging.

CTD Guide for APDMs 67   non-permanent structures. Although most DOTs interviewed for this research indicated that they allow contractors to perform early work, all of them unanimously emphasized that this should be done at the contractor’s own risk. 4.3 Preconstruction Period e preconstruction period has been discussed as being the period needed to conduct the necessary design and other required activities to permit the rst construction work package to be RFC. Timeline-wise, it is the time between the contract award and the RFC of the rst work package, as shown in Figure 4-4. It includes the duration to furnish the complete set of designs deliverable for the rst work package as well as major preconstruction activities, such as per- mit applications and ROW acquisition, that must be done prior to the construction of the rst work package. e preconstruction period involves both external and internal domains. Given the important and iterative nature of preconstruction planning, this section in the guidebook presents information on determining the preconstruction period (Step 2) before moving on to detail the other steps in the procedure. e current research identied two primary approaches that state DOTs use to establish the preconstruction duration: (1) use of professional judgment by experienced DOT project man- agers; and (2) use of general principles for adding a range of days to the estimated construction period. Based on interviews with multiple DOTs experienced in alternate project delivery, a sys- tematic four-step procedure has been established to determine the duration of a preconstruction period. e four steps apply to preconstruction activities for each work package that has been identied as a design work package (i.e., a work package that is completed before the end of the design phase). is means they function as sub-steps of both Step 1 and Step 2 in the overall CTD procedure for APDM projects (see Figure 4-5 and Figure 4-6). Figure 4-4. Preconstruction period.

68 Systematic Approach for Determining Construction Contract Time: A Guidebook Figure 4-5. Four-step procedure to determine preconstruction duration for APDM projects. Figure 4-6. Overall CTD procedure for APDM projects.

CTD Guide for APDMs 69   4.4 Generic CTD Procedure for APDM Figure 4-6 presents a four-step generic CTD procedure to determine the overall contract time of APDM (i.e., preconstruction time and construction time). 4.4.1 Steps 1 and 2—Establish Work Packages and Determine the Preconstruction Period Work packaging is the key to shorter delivery time of APDM projects because it allows some design tasks and construction activities to be performed simultaneously. e rst step in devel- oping the overall contract time for an APDM project is to establish the required work packages. A work package is dened as a major component of the project’s scope of work from develop- ment through delivery. Although the project’s nal plans are not yet available during this pro- cess, it is crucial to understand the project’s goals and its scope of work to be able to come up with the appropriate number and sequence of work packages. Determining the preconstruction period (Step 2 in the Generic CTD Procedure for APDM) involves four sub-steps whose completion contributes to the execution of both Step 1 and Step 2. Accordingly, this section of the guidebook presents the sub-steps as relating to both Step 1 and Step 2. Next, Figure 4-7 provides additional details about Step 1, and Figure 4-8 provides an overview that summarizes key aspects of this step. Next, Figure 4-9 breaks down the sub-steps taken to identify design work packages. e overview in Figure 4-10 summarizes key aspects of this procedure. Finally, Figures 4-11 through 4-16 detail the four sub-steps used to identify design work packages and preconstruction activities and milestones, establish preconstruction activity duration, and determine the preconstruction duration. Step 1 Establish Work Packages Determine Preconstruction Period and Step 2 Sub-Step 1—Establish work packages. Obtain and review the most-up-to-date design drawings from the design team. Review preliminary maintenance of traffic (MOT) plans, staging plans, phasing plans, preliminary environmental documents, and the like to identify any potential constraints on construction work activities. Find the best way to break down the entire project into multiple, smaller work packages that facilitate the concurrency between design and construction activities (e.g., location-based, section-based). The four sub-steps that contribute to both establishing work packages (Step 1) and determining the preconstruction period (Step 2) are further detailed in Figures 4-9 through 4-16. Establish work packages Figure 4-7. Sub-Step 1—Establish work packages.

70 Systematic Approach for Determining Construction Contract Time: A Guidebook Emerging technology. Not applicable. Pros and cons. Not applicable. The methods and tools used in this step. • This step is to be done manually. • Consult with project team members (e.g., project managers) for their advice on how to split up the proposed work. The outcome of this step. A list of work packages that, collectively, contains all work in the proposed contract. Required documents and information. State regulations, federal or state agency guidelines, standard specifications, project requirements, project’s scope of work, RFP draft, preliminary design plans, preliminary MOT plans, preliminary staging/phasing plans, preliminary environmental documents, and others. Figure 4-8. Overview of Sub-Step 1—Establish work packages. Step 1 Establish Work Packages Determine Preconstruction Period and Step 2

CTD Guide for APDMs 71   Sub-Step 2—Establish design work packages. • Identify design work packages that constrain the release of the first work package for construction. • The following design packages should NOT be included in the preconstruction period: i. Those that will be completed when the project is advertised (i.e., most of the work will be done within the RFP development stage). ii. Those that cannot be completed until the construction NTP is issued. Establish design work packages Identify preconstruction activities & milestones Estimate preconstruction activity duration Determine preconstruction duration Figure 4-9. Sub-Step 2—Establish design work packages. Step 1 Establish Work Packages Determine Preconstruction Period and Step 2 Sub-Step 2—Identify Design Work Packages One aspect of establishing work packages is identifying design work packages. is sub-step contributes to Sub-Step 1, but it is important enough to merit a separate discussion. Figure 4-9 details this sub-step, and the overview in Figure 4-10 summarizes key aspects of this procedure. For a work package to begin construction, all design documents associated with the work package must be approved and released for construction. us, the preconstruction period is the time necessary to reach RFC for the rst work package.

72 Systematic Approach for Determining Construction Contract Time: A Guidebook Pros and cons. Not applicable. The outcome of this step. A list of the design work packages that need to be completed during the preconstruction period. The methods and tools used in this step. • Examples of design work packages: o Context (economic/business properties). o Planning (project goals, purpose and need). o Local agency/stakeholder. o ROW/land management (easements, land leasing). o Environmental/natural resources (permits, commitments). o Utilities (prior rights, agreements, negotiations). o Design—structural (bridges, other structures). o Design—mobility (roadway geometrics, assets within ROW). o Design—drainage/hydraulics (stormwater management, drainage assets). o Design—traffic (signage, lighting, signals). o Construction (constructability, sequencing, phasing). • Tool T4.1 has been developed as a spreadsheet-based tool to help with this step (see Appendix A). Emerging technology. Not applicable. Required documents and information. A list of work packages (obtained in Step 1—Establish Work Packages). Figure 4-10. Overview of Sub-Step 2—Establish design work packages. Step 1 Establish Work Packages Determine Preconstruction Period and Step 2

CTD Guide for APDMs 73   Sub-Step 3—Identify Preconstruction Activities and Milestones Preconstruction period design activities are those that take the design shown in the RFP and advance it to the point where the rst design work package is released for construction. It is recom- mended not to overcomplicate the preconstruction schedule by placing too many activities in this step, as it is meant to generate a high-level estimate given the limited amount of project information available at this stage. Figure 4-11 details the two critical tasks required to execute the sub-step, “Identify preconstruction activities & milestones,” and the overview in Figure 4-12 highlights key aspects of this part of the procedure. Sub-Step 3a—Identify preconstruction activities. • List the major activities required to complete each design work package (identified in the sub-step labeled “establish design work packages”). • For each design work package, examples of activities include but are not limited to preparing geotechnical reports, finalizing foundation designs, designing culverts, developing grading plans, developing MOT plans, and more. • For each non-design-related work package, examples of activities include but are not limited to completing subsurface utility engineering (SUE) surveys, negotiating agreements, applying for permits, performing relevant ROW acquisition activities, and the like. Sub-Step 3b—Identify design/preconstruction milestones. Identify and list all potential milestones that will constrain the preconstruction schedule. Identify preconstruction activities Identify design/ preconstruction milestones Establish design work packages Identify preconstruction activities & milestones Estimate preconstruction activity duration Determine preconstruction duration Figure 4-11. Tasks in Sub-Step 2—Identify preconstruction activities and milestones. Step 1 Establish Work Packages Determine Preconstruction Period and Step 2

74 Systematic Approach for Determining Construction Contract Time: A Guidebook Pros and cons. Not applicable. Emerging technology. Not applicable. The methods and tools used in this step. • Recommended methods for this step include a brainstorming session, referring to past similar projects, and the like. • Tool T4.2 has been developed as a spreadsheet-based tool to facilitate this step (see Appendix A). The outcome of this step. A preconstruction work breakdown structure, with each preconstruction work package further broken down into several major activities. A list of milestones/deadlines with regard to the design phase of the project. Required documents and information. A list of the design work packages that need to be completed before the RFC of first work package (obtained in the sub-step labeled “establish design work packages”). Any known commitments regarding the design stage (dictated by owner agency or other external parties). Figure 4-12. Overview of Sub-Step 2—Identify preconstruction activities and milestones. Step 1 Establish Work Packages Determine Preconstruction Period and Step 2

CTD Guide for APDMs 75   Sub-Step 4—Establish Preconstruction Activity Duration Unlike construction activities, the majority of preconstruction activities lack established pro- duction rates. is situation may be intimidating; however, by leveraging the right resources, along with some sound professional judgment, a reasonable duration estimate can be made. Figure 4-13 details the procedure for this sub-step and the overview in Figure 4-14 summarizes key aspects of the procedure. Sub-Step 4—Estimate preconstruction activity duration. • Estimate the duration for each preconstruction activity. • Potential resources to consult for the completion of this task include: Design consultant/engineers who have produced the preliminary design and plans of the project. APDM project database (if available)—Review multiple past APDM projects to obtain an agency- specific estimate. Similar DBB project(s)—Use the design timeline of similar DBB projects as a baseline. Adjust the duration accordingly to account for the fact that some work is done in the RFP stage and/or to consider any potential efficiency gain in the design process. General principles. Professional experience and engineering judgement—Since APDMs are usually chosen to achieve project-specific objectives that could not be achieved by traditional DBB methods, professional judgement is essential in determining the reasonableness of the duration estimate obtained from all sources. Apply necessary adjustments to properly reflect the salient features and/or objectives of the project. Estimate preconstruction activity duration Establish design work packages Identify preconstruction activities & milestones Estimate preconstruction activity duration Determine preconstruction duration Figure 4-13. Tasks in Sub-Step 4—Estimate preconstruction activity duration. Step 1 Establish Work Packages Determine Preconstruction Period and Step 2

76 Systematic Approach for Determining Construction Contract Time: A Guidebook The outcome of this step. Duration estimate for each preconstruction activity. Pros and cons. Not applicable. The methods and tools used in this step. • Consider using program evaluation and review technique (PERT) to estimate duration of an activity. PERT uses three duration estimates (e.g., most likely, optimistic, pessimistic) to establish a weighted-average duration. • For a reliable duration estimate, the duration length should be proportional to the level of schedule risk of the activity under consideration. A tool has been developed to identify potential issues that are most likely to have an impact on the duration of preconstruction activities (see Appendix A: Tool T4.2). Alternatively, if a risk workshop had been conducted, review the risk register to assess the level of schedule risk on respective preconstruction activity. • If multiple issues/risks are anticipated, depending on the mitigation measures, adjustment to the duration may be necessary. Emerging technology. Not applicable. Required documents and information. List of preconstruction activities created from the sub-step labeled “estimate preconstruction activity duration.” A thorough understanding of the project status and requirements (e.g., permit timeline, project progress, schedule identified from the risk workshop). Figure 4-14. Overview of Sub-Step 4—Estimate preconstruction activity duration. Step 1 Establish Work Packages Determine Preconstruction Period and Step 2

CTD Guide for APDMs 77   Sub-Step 5—Determine Preconstruction Duration is sub-step involves sequencing the preconstruction activities on a timeline. e sequence takes into consideration the relationships (i.e., precedence) between the activities. e nal esti- mate of preconstruction duration is obtained aer making necessary adjustments to comply with the constraints that were identied in the earlier sub-step, labeled “identify preconstruction activities and milestones.” Figure 4-15 presents the tasks involved in determining the nal dura- tion estimate, and the overview provided in Figure 4-16 summarizes key aspects of this sub-step. Sub-Step 5a—Develop a preconstruction schedule. • Develop a schedule for the preconstruction period (based on the identified activities and their respective durations). • Use of CPM software is recommended, particularly for complex projects. If CPM software is used, the preconstruction CPM schedule should be integrated with the construction CPM schedule by connecting the completion of appropriate design activities with the first construction activity in each work package. • At minimum, develop a bar chart to illustrate the precedence of activities in the preconstruction period. Keep in mind that some activities may be performed concurrently. Calculate the longest duration from the start of the first preconstruction activity to the completion of the final preconstruction activity. Sub-Step 5b—Determine the final duration estimate. • Check to see whether the preconstruction schedule complies with the milestone(s) identified in the sub-step labeled “Identify preconstruction activities and milestones.” • Adjust the schedule as required to meet the milestone constraints. Determine final duration estimate Establish design work packages Identify preconstruction activities & milestones Estimate preconstruction activity duration Determine preconstruction duration Figure 4-15. Tasks in Sub-Step 5—Determine preconstruction duration. Step 1 Establish Work Packages Determine Preconstruction Period and Step 2

78 Systematic Approach for Determining Construction Contract Time: A Guidebook The outcome of this step. A complete schedule (CPM or bar chart) for the preconstruction period. Preconstruction duration. The civil design work package example shows how this approach permits the inclusion of administrative and logistical activities associated with construction to facilitate optimizing the design and construction schedules with each other. Four DOTs experienced with APDMs have shared the general principles they use for preconstruction duration: • Caltrans: 4–6 months; • Georgia DOT: 6–9 months; • Utah DOT: 3–4 months; and • Virginia DOT: 4 months. Required documents and information. A list of preconstruction activities with their respective duration estimate. Relationship (precedence) between activities. Figure 4-16. Overview of Sub-Step 5—Determine preconstruction duration. Step 1 Establish Work Packages Determine Preconstruction Period and Step 2

CTD Guide for APDMs 79   Step 3 Determine Construction Period 4.4.2 Step 3—Determine the Construction Period e process used to determine the duration required for the construction phase of an APDM project is fundamentally similar to the process used to determine the construction contract time of a traditional DBB project. e few key dierences arise because an APDM project typi- cally goes into the advertisement stage without full, detailed design information. As a result, the construction duration of an APDM project can only be determined using a high-level critical path method (CPM) schedule employing estimated quantities of major work items, and it is typically accompanied by more assumptions than its DBB counterpart. Figures 4-17 and 4-18 detail the sub-steps, and the overview in Figure 4-19 summarizes key aspects of this step. Establish construction work packages List major activities and their corresponding quantities Establish project -specific production rate Sub-Step 1—Establish construction work packages. • The scope of work in each construction work package should closely follow the design package, which produces design deliverables that will enable the execution of the corresponding construction work. Sub-Step 2—List major activities and their corresponding quantities. • This step should be performed separately for each work package. • Identify the major activities in each work package. This list does not need to be exhaustive, but it does need to include all activities that will most likely drive the schedule of the work package. The consensus among DOTs experienced in APDM is that there is no need to invest more effort than is necessary to determine the contract time of an APDM project. • Estimate the quantity needed for each work activity. Use the quantity associated with each package. For example, if the excavation work spans two work packages (e.g., Phase 1 and Phase 2), then the excavation quantity in each phase needs to be determined individually. • Consult the design team to establish work quantities. Recognize the fact that it is nearly impossible to obtain 100% accurate quantities at this stage. The goal is to make an educated guess about the most probable amount of work for each activity. Sub-Step 3—Establish project-specific production rate. • Production rates must reflect site conditions and be achievable by typical contractors. • Assume normal working hours unless project acceleration is necessary. • Refer to Figure 2-8 of the DBB CTD procedure for more information. Figure 4-17. Sub-Steps 1–3 in Step 3—Determine the construction period.

80 Systematic Approach for Determining Construction Contract Time: A Guidebook Step 3 Determine Construction Period Sub-Step 4—Calculate a duration for each activity. For a work item with quantity, the duration of the item is calculated by dividing the given quantity by the production rate estimated in the previous step. Sub-Step 5—Establish the construction logic. Determine the sequence of work by examining the precedence relationship between work activities. Sub-Step 6—Estimate the construction duration. • It is recommended that CPM scheduling software be used for this purpose because: Work packaging (in both design and construction) increases the project’s schedule complexity. CPM scheduling software is able to incorporate and determine the impact of project acceleration strategies. It is more capable of handling milestones or schedule constraints (e.g., winter shutdown period, environmental windows, interim completion dates). • Identify any milestone or schedule constraints on construction activities. These constraints may arise from permit requirements, MOT plans, specification requirements of certain work activities, and more. Impose these constraints and/or milestones when developing the CPM schedule. • Make assumptions necessary to develop the CPM schedule. It is normal to have more assumptions in an APDM project than in a DBB project reflecting an insufficient amount of project information available when the contract time needs to be determined. • Document each assumption made, both to facilitate the schedule review process and to make sure changes to the schedule can be made easily whenever there is a need to modify any assumption. Estimate construction duration Establish construction logic Calculate duration for each activity Figure 4-18. Sub-Steps 4–6 in Step 3—Determine the construction period.

CTD Guide for APDMs 81   Step 3 Determine Construction Period The outcome of this step. A construction-schedule project duration estimate. Pros and cons. Not applicable. The methods and tools used in this step. Spreadsheet-based tools or commercial scheduling software programs. Emerging technology. Not applicable. Required documents and information. Preliminary design plans, specifications, agencies’ guidance and manuals (including CTD manuals), and a list of bid items and corresponding quantities. Figure 4-19. Overview of Step 3—Determine the construction period.

82 Systematic Approach for Determining Construction Contract Time: A Guidebook 4.4.3 Step 4—Determine APDM Contract Time is nal step resembles the CTD procedure for DBB projects, except that the project duration now consists of a preconstruction duration and a construction duration. Figures 4-20 and 4-21 provide details about the sub-steps for Step 4, and the overview presented in Figure 4-22 sum- marizes key aspects of this step. Step 4 Determine APDM Contract Time Sub-Step 1—Estimate the total contract duration. • The total contract duration can be computed using the following formula: APDM contract time = preconstruction duration + construction duration. • The duration type (e.g., working days) must be the same for both periods when performing this calculation. Adding two periods that have different duration types will yield inaccurate results. • If both schedules (i.e., preconstruction and construction) were developed using CPM software (in a single schedule), the program can easily (and more accurately) calculate the total contract duration. Sub-Step 2—Determine milestones and completion date constraints. Identify milestones or constraints on the overall project schedule. Sub-Step 3—Select the type of contract time. • The contract time of an APDM project is typically expressed in the following two ways: Number of calendar days. Complete by a certain date. • Refer to DBB CTD procedure Step 3 for more guidance. • Consider using interim completion dates for projects with significant phasing. Select the type of contract time Estimate total contract duration Determine milestones & completion date constraints Figure 4-20. Sub-Steps 1–3 in Step 4—Determine APDM contract time.

CTD Guide for APDMs 83   Step 4 Determine APDM Contract Time Sub-Step 4—Convert working days to calendar days. This step will be necessary if the preconstruction period and/or construction period have been calculated in terms of working days (usually the case when a bar chart is used). • Refer to Step 4 in the DBB CTD procedure for more guidance (see Chapter 2). • If the project is determined to be a completion date contract, the tentative completion date is found by using the following formula: Tentative completion date = expected contract start date + number of calendar days. Sub-Step 5—Determine the final contract time. • Check whether the tentative contract time satisfies all the constraints identified in Sub-Step 2 (Figure 4-20). • Apply adjustments if necessary. • Consider using acceleration strategy if the tentative contract time does not meet the milestone/completion constraints. See the section on “Project Acceleration Strategies” in this chapter for guidance on applying acceleration strategies. • Finalize the contract time estimate with the type of contract time that was decided in Sub-Step 3 (Figure 4-20). Convert working days to calendar days Determine final contract time Figure 4-21. Sub-Steps 4 and 5 in Step 4—Determine APDM contract time.

84 Systematic Approach for Determining Construction Contract Time: A Guidebook Step 4 Determine APDM Contract Time The outcome of this step. Contract time to be specified on the RFP. The methods and tools used in this step. • This step can be done manually (using bar charts or conversion tools). • Alternatively, CPM software can be used to generate a more accurate contract time estimate. The impact of an acceleration strategy is also more easily determined using CPM software. Required documents and information. Preconstruction schedule (obtained from Step 2), construction schedule (obtained from Step 3). Additional guidance for this step. This sample table shows how the contract time of each APDM is determined: Delivery Method Construction Period (Days) Preconstruction Period (Days) Contract Time (Days) Remarks DBB 200 N/A 200 CMGC 200 N/A 200 CTD is for the construction contract only. The preconstruction period runs concurrently with the design period. DB 200 90 290 P3 200 90 290 Figure 4-22. Overview of Step 4—Determine APDM contract time.

CTD Guide for APDMs 85   4.5 Project Acceleration Strategies Based on interview ndings, most DOTs with APDM experience typically assume no project acceleration when developing the default CPM schedule. If project acceleration is deemed utterly necessary to meet an aggressive deadline, then dierent strategies can be used to compress the schedule. Acceleration strategies may include but are not limited to: • Higher production rates, • Concurrent work, • Scheduling 6 working days per week, and • Use of multiple crews. Care is warranted when applying any acceleration strategy. e risk of the construction schedule increases exponentially with each additional acceleration strategy that is incorporated into the schedule. us, this schedule-crashing process should be an iterative process in which strategies are added one at a time until the estimated completion date meets the required deadline. Agencies are advised to always check whether it is reasonable to perform this acceleration tech- nique, being careful to consider both the site conditions and the capacity of the contracting community. In addition, the agency should make it clear in the RFP whether project acceleration is required from the contractor. 4.6 References Antoine, A. L., D. Alleman, and K. R. Molenaar (2019). “Examination of project duration, project intensity, and timing of cost certainty in highway project delivery methods.” Journal of Management in Engineering, 35(1), 04018049. FHWA (2006). Design-Build Eectiveness Study—As Required by TEA-21 Section 1307(f): Final Report. Federal Highway Administration, Washington, D.C. Gransberg, D. D., and K. R. Molenaar (2019). “Critical comparison of progressive design-build and construction manager/general contractor project delivery methods.” Transportation Research Record: Journal of the Trans- portation Research Board, 2673(1), 261–268. Available at: https://doi.org/10.1177%2F0361198118822315. Lopez el Puerto, C., D. D. Gransberg, and M. C. Loulakis (2017). “Contractual approaches to address geotechnical uncertainty in design-build public transportation projects.” Journal of Legal Aairs and Dispute Resolution in Engineering and Construction, 9(1), 04516010. Available at: http://dx.doi.org/10.1061/(ASCE)LA.1943- 4170.0000202. Mendez, V. (2010). Every Day Counts: Innovation Initiative. Federal Highway Administration, Washington, D.C. Scott, S., K. R. Molenaar, D. D. Gransberg, and N. C. Smith (2006). NCHRP Report 561: Best-Value Procurement Methods for Highway Construction Projects. Transportation Research Board of the National Academies, Washington, D.C. Available at: http://www.trb.org/Publications/Blurbs/158046.aspx. Songer, A. D., and K. R. Molenaar (1996). “Selecting design-build: Public and private sector owner attitudes.” Journal of Management in Engineering, 12(6), 47–53. Available at: https://doi.org/10.1061/(ASCE)0742- 597X(1996)12:6(47).

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Contract time affects the cost of construction, traffic disruption and public inconvenience, the economic impact of projects to the surrounding areas, and schedule risks.

The TRB National Cooperative Highway Research Program's NCHRP Research Report 979: Systematic Approach for Determining Construction Contract Time: A Guidebook provides state departments of transportation guidance for producing consistently credible, reliable, and defensible contract time estimates.

Supplemental to the report is NCHRP Web-Only Document 298: Developing a Systematic Approach for Determining Construction Contract Time, a spreadsheet-based Toolkit, a Technical Memorandum, and a Presentation.

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