Work Zone Mobility and Safety Program

5.0 Significant Projects

Some projects are likely to have much greater effects on traffic conditions in and around their work zones than other projects will. So it is reasonable to pay more attention to the effects of certain projects, such as those that we think will cause greater congestion, compromise road safety, or greatly reduce access to businesses or event venues (e.g., stadiums, arenas). Recognizing that not all road projects cause the same level of work zone impacts, the updated Rule (the Rule) establishes a category of projects called "significant projects." This Section provides an overview and general guidance for identifying significant projects.

5.1 Overview

5.1.1 What is a Significant Project?

Simply stated, a significant project is a project that a State or local transportation agency [1] expects will cause a relatively high level of disruption. The Rule provides a specific, more detailed definition of significant project in § 630.1010:

  • A significant project is defined as one that, alone or in combination with other concurrent projects nearby, is anticipated to cause sustained work zone impacts [2] that are greater than what is considered tolerable based on State policy and/or engineering judgment.

While the Rule gives agencies flexibility in determining their own definitions for significant project, the Rule does specifically state that projects meeting a certain set of criteria are automatically classified as significant projects. The Rule does allow for agencies to apply for and Federal Highway Administration (FHWA) Division Offices to grant exceptions to the requirements triggered by the automatic classification. The Rule states that, in addition to projects meeting the agency's own definition of significant:

  • All Interstate system projects within the boundaries of a designated Transportation Management Area (TMA) that occupy a location for more than three days with either intermittent or continuous lane closures shall be considered as significant projects. For an Interstate system project or categories of Interstate system projects that are classified as significant through the application of this provision, but in the judgment of the State they do not cause sustained work zone impacts, the State may request from the FHWA, an exception to the requirements triggered by the classification. Exceptions to these provisions may be granted by the FHWA based on the State's ability to show that the specific Interstate system project or categories of Interstate system projects do not have sustained work zone impacts.

5.1.2 Related Provisions in the Rule

The Rule requires that agencies identify significant projects. The requirements for significant projects, outlined in § 630.1010, state that:

  • The agency must identify upcoming projects that are expected to be significant.
  • This identification of significant projects should be done as early as possible in the project delivery and development process, and in cooperation with the FHWA.
  • The agency's work zone policy provisions, the project's characteristics, and the magnitude and extent of the anticipated work zone impacts should be considered when determining if a project is significant or not.

Whether or not a project is considered to be significant determines which transportation management plan (TMP) requirements apply to the project. TMP requirements are discussed in Section 6.0 of this document.

5.1.3 What is the Purpose of Identifying Significant Projects?

The classification of certain projects as significant is intended to help agencies allocate resources more effectively to projects that are likely to have greater impacts. The classification process is also intended to help agencies think through project coordination and scheduling issues. A project that is expected to cause greater work zone impacts may warrant additional attention during the project delivery process and additional funding for transportation management strategies that help manage the work zone impacts of the project. Since decisions on project budgets, the sequencing of projects, and major design decisions are generally made early in the program delivery process, the classification of projects should be made as early as possible when the most options are available.

Classifying projects as early as possible in program delivery will help answer questions like:

  • What are the potential work zone impacts of identified projects? Do the work zone aspects of the project warrant particular attention during the project delivery process? Are the expected work zone impacts for a project great enough that the project should be considered a significant project?
  • What are the cumulative work zone impacts of multiple road projects taking place at the same time on transportation system safety and mobility?
  • What are the coordination issues, if any, that need to be accounted for in planning and scheduling multiple projects in the vicinity of each other?
  • What are the potential work zone management strategies that may be used for a project?
  • What is the likely range of costs of the potential strategies to manage the work zone impacts of the project?
  • What are the design implications and effects on project scheduling/phasing/staging of the potential management strategies?

5.2 When in Program Delivery Should Significant Projects Be Identified?

Significant projects should be identified during the systems planning phase of project delivery, when Statewide Transportation Improvement Programs (STIPs) and regional Transportation Improvement Programs (TIPs) are developed. This stage of project delivery involves the identification of needs and deficiencies in the transportation system for both the long term and the short term, and the development of appropriate improvement recommendations. Long-term transportation plans are usually projected out 20 to 25 years, while short-term plans are smaller packages of projects that cover timeframes ranging from two to six years. Systems-level planning can be performed at several levels: statewide, regional, metropolitan, and local jurisdiction (city, county, township, village, highway district, etc.). The process is interactive, with participation and feedback from concerned agencies, interested parties, and the public.

Consideration of the impacts of work zones at the systems-planning level (either on a network-wide basis or corridor basis) can have several positive effects. For example, in cost estimation and budgeting for projects, an understanding of the expected level of work zone impacts of the road project will help in deciding what transportation management strategies are likely. This understanding can then serve as the basis for developing reasonable cost estimates that are commensurate with the impacts of the project. Further, the analysis of the cumulative impacts of concurrent road projects will help better schedule construction thereby minimizing the impacts on road users, businesses, and other affected parties.

Currently, work zone considerations are not always accounted for in the systems planning processes, although State Departments of Transportation (DOTs), Metropolitan Planning Organizations (MPOs), and other agencies generally realize the potential value of such considerations. Where work zone considerations are not considered in the systems planning process, systems planning processes should be amended to incorporate work zone considerations.

While making the initial identification of significant projects during systems planning is recommended, an agency may need to reconfirm whether a project is significant or not during subsequent project development stages. During actual project development more project specific information becomes available for making project-specific decisions. As a result, certain projects that were thought to be significant may no longer be significant as a result of change in certain circumstances, and vice-versa. For example:

  • A project's design may have changed, resulting in different project staging that affects traffic conditions differently.
  • Another project nearby may have been accelerated a year to address critical safety issues, causing two nearby projects to now be concurrent. Their cumulative effects may now mean the projects should be considered significant.
  • Project schedules change. Changing delivery dates may cause a change in expected work zone impacts that leads to a change in whether a project is significant or not.

5.3 Identifying Significant Projects

As noted previously, the Rule gives agencies some flexibility in determining their own criteria for significant projects. While the Rule specifies that Interstate projects meeting certain criteria are automatically considered significant, there are many other road projects on State and local roads, as well as many Interstate projects, that do not fall under those criteria. Agencies will need to develop their own definitions and include those definitions in agency policy or procedures so they can be applied consistently. The agency policy or procedures should also define who determines significant project classifications.

The process of identifying significant projects may either be qualitative or quantitative. During systems planning, most of the assessment is primarily qualitative based on available information and engineering judgment. During the subsequent stages of project development, including preliminary engineering and design, the agency may choose to reconfirm a project's significance by conducting more detailed quantitative analyses. The agency and its project partners, including the FHWA, and other appropriate regional stakeholders, ideally should work together as a multi-disciplinary team to identify significant projects.

5.3.1 Possible Criteria for Identifying Significant Projects

The Rule encourages agencies to make significant project determinations based on their work zone policy provisions, a project's characteristics, and the magnitude and extent of the anticipated work zone impacts for a project. A combination of qualitative and quantitative criteria should be used, as appropriate, to identify significant projects. An essential aspect in using criteria for significant projects is to realize that different projects have unique circumstances and needs, and any set of criteria should be applied taking this into account.
Qualitative criteria are subjective, and leave much room for interpretation along different perspectives. This can both be an advantage and a disadvantage. But in most cases, during systems planning, which is when the initial identification of significant projects is conducted, adequate information may not be available to quantitatively assess whether a project is significant.

Quantitative methods to identify significant projects during systems planning may be appropriate for major projects. Quantitative criteria for significant projects are best suited for reconfirming project significance during the subsequent stages of project development, especially during design. For example, they can be used to identify whether a project that was previously not considered significant, becomes significant as a result of combining it with another concurrent project. Quantitative criteria will facilitate the use of thresholds for hard numbers like expected delay, queue length, and user-cost for determining project significance.

The following are some of the possible elements to consider in identifying which projects are significant.

Project characteristics, including:

  • Project type.
  • Project size, extent/length, duration, cost, and complexity.
  • Type of work being performed.
  • Type of work zone (full closure, lane reduction, cross-over, night work, etc.).
  • Project schedule.
  • Planned lane closures.
  • Roadway classification.
  • Area type (urban, suburban, rural).

Travel and traffic characteristics, including:

  • Traffic volumes.
  • Seasonal and temporal variations in volumes (hourly, daily, or weekly).
  • Percentages of different vehicular volumes (cars, trucks, or buses).
  • Type of travel (commuter or tourist), freight corridor, transit corridor.
  • Public and private facility access issues (e.g., park and ride lots, manufacturing plants with shift changes).
  • Occurrence of special events (e.g., concerts, parades).
  • Potential impacts of weather.

Work zone characteristics, including:

  • Impacts of the project at both the corridor and network levels to include parallel corridors, alternate routes, the transportation network, and other modes of transportation, impacts of other concurrent work zones in the vicinity of the project, either at the corridor level or the network level. For example, will the project impact the traveling public at the metropolitan level, or the regional level, or the statewide level?
  • Capacity issues (lane reductions, lane configurations).
  • Level of public interest in the project.
  • Number of travelers that will be impacted and/or level of user cost impacts.
  • Expected safety impacts.
  • Expected delay and travel time/delay and travel time thresholds.
  • Impacts on nearby transportation infrastructure, such as, key intersections and interchanges, railroad crossings, public transit junctions, and other junctions in the transportation network.
  • Impacts on evacuation routes in the vicinity of critical transportation or other infrastructure.
  • Impacts on affected public properties, including schools, parks, recreational facilities, fire stations, police stations, and hospitals.
  • Impacts of the project on affected private properties, including businesses and residences.

A combination of the above criteria can be used to form a framework for identifying and categorizing significant projects. For example, one possible framework is to use criteria such as whether a project, alone or in combination with other concurrent projects nearby, is anticipated to have one or more of the following characteristics:

  • It will impact the traveling public at the metropolitan or regional level (and possibly more broadly).
  • It has a high level of public interest.
  • It will directly impact a moderate to high number of travelers.
  • It will have high user cost impacts.
  • The duration is moderate to long.

Another example of a possible framework for identifying and categorizing significant projects is from FHWA's Work Zone Self Assessment (WZSA). [3] The WZSA divides projects into four different categories using qualitative criteria. With a project classification framework such as the one in the WZSA, an agency can designate certain project categories as significant projects (e.g., all projects falling into the Type I and Type II project categories are considered significant).

  • Type I. Work impacts the traveling public at the metropolitan, regional, intrastate, and possibly at the Interstate level. It has a very high level of public interest. It will directly impact a very large number of travelers. It will have significant user cost impacts and the duration is usually very long. Examples of this work type would be: Central Artery/Tunnel in Boston, Massachusetts; Woodrow Wilson Bridge in Maryland/Virginia/District of Columbia; Springfield Interchange "Mixing Bowl", Springfield, Virginia; and I-15 reconstruction in Salt Lake City, Utah.
  • Type II. Work impacts the traveling public predominately at the metropolitan, and regional level. It has a moderate to high level of public interest. It will directly impact a moderate to high number of travelers. It will have moderate to high user cost impacts and the duration is usually moderate to long. Examples of this work type would be: major corridor reconstruction, high impact interchange improvements, full closures on high volume facilities, major bridge repair, repaving projects that require long term lane closures, etc.
  • Type III. Work impacts the traveling public at the metropolitan or regional level. Has a moderate level of public interest. It will directly impact a low to moderate level of travelers. It will have low to moderate user cost impacts, and can include lane closures for a moderate duration. Examples of this work type would be: Repaving work on roadways and the National Highway System (NHS) with moderate average daily traffic (ADT), minor bridge repair, shoulder repair and construction, minor interchange repairs, etc.
  • Type IV. Work impacts the traveling public to a small degree. Public interest is low. Duration of work is short to moderate. Work zones are usually mobile, and typically this work is recurring. Examples of this work type would be: Certain low impact striping work, guardrail repair, minor shoulder repair, pothole patching, very minor joint sealing, minor bridge painting, sign repair, mowing, etc.

The design chapter of Wisconsin DOT (WIDOT) Facilities Development Manual provides guidance to assist designers through the process of anticipating serious congestion on the Wisconsin freeway system. Guidance like this can be used in developing criteria for significant projects. The following are excerpts of some of the guidance:

User delay greater than 30 minutes above what is considered usual delay for the specific project is unacceptable and needs to be addressed when that project is on the C2020 system.

Rural drivers are typically less tolerant of delay than urban drivers. Likewise northern Wisconsin drivers will generally be less tolerant of delay than drivers in southeastern Wisconsin.

A 1-mile queue of traffic will take approximately 10-15 minutes to dissipate. Therefore, a queue greater than 2-3 miles is unacceptable and mitigation measures must be taken.

In general, if a freeway experiences greater than 25,000 ADT (2-way) and only one lane of traffic is provided in each direction, serious traffic delays will result. If the freeway project in question will have one lane in each direction and experiences between 20,000 and 25,000 ADT (2-way) it may have congestion problems and serious delays on summer weekends.

Source: State of Wisconsin, Department of Transportation, Facilities Development Manual, Procedure 11-50-22, Chapter 11 Design, Section 50 General Design Considerations, Subject 22 Work Zone Traffic Congestion and Mitigation, February 2003.

5.3.2 Use of Analytical Tools

Analytical tools can be helpful for assessing whether a project meets an agency's quantitative criteria for significant projects. These tools can be used to help an agency assess whether there is adequate capacity to handle the expected traffic volumes through the project, and whether any queues are likely to form. They can also provide estimates of the most likely times when any queues would form and how long they might be. For an agency that chooses to use queue length as part of its criteria for significant projects, analytical tools would be valuable for evaluating this criterion. They can also be used to assess how a project will likely impact nearby areas, such as alternate routes or access to a local business district.

Analytical tools can also be used to identify, and evaluate the likely effects of, potential work zone management strategies, such as changing the allowable work hours on a project.

Some tools that can be used alone or in combination are:

  • Sketch-planning and systems planning analysis tools like travel demand modeling tools, the ITS Deployment Analysis System (IDAS), etc.;
  • Higher-level project impacts analysis tools like Highway Capacity Manual (HCM)-based tools, QuickZone, QUEWZ, Micro-BenCost, etc.; and
  • Operational-level traffic analysis and simulation tools like VISSIM, PARAMIX, CORSIM, NETSIM, etc.

5.4 Exception Process

The Rule specifies that all Interstate system projects within the boundaries of a designated Transportation Management Area (TMA) that occupy a location for more than three days with either intermittent or continuous lane closures shall be considered as significant projects. FHWA recognizes that not all projects that fall in this category will cause a high level of disruption, even though they are on major facilities or involve lengthy closures. For example, if the lane-closure occurs at night, or if the lane-closure is only during off-peak and weekend hours, or if the type of work is minor maintenance work, or if the roadway capacity significantly exceeds the traffic volumes, the project may not have a high level of work zone impacts. Therefore, the Rule provides for an exception clause for those Interstate system projects, or classes of projects, that are deemed to be significant according to the Rule, but in reality, may not have a high level of sustained work zone impacts. For such projects that are classified as significant through the application of this provision, but in the judgment of the agency they do not cause sustained work zone impacts, the agency may request an exception, from the FHWA Division Office, to the requirements triggered by the classification. Exceptions to these provisions may be granted by the FHWA Division Office based on the agency's ability to show that the specific Interstate system project or categories of Interstate system projects do not have sustained work zone impacts.

The agency may use either qualitative or quantitative criteria and methods (or a combination of both) to illustrate that the specific project or categories of projects will not have sustained work zone impacts. The agency can submit an appropriate exception request to the FHWA Division Office, which will then work with the agency to review the request and take appropriate action.

Blanket exceptions for certain categories of projects may be sought by the agency if the agency determines that such projects will not have sustained impacts, and can demonstrate the same to the FHWA. Some examples of Interstate system projects that might qualify for blanket exceptions include:

  • Road work on Interstate projects where the capacity far exceeds the demand (e.g., single lane closures on highways that have low volumes of traffic;)
  • Night work on certain Interstate routes; and
  • Off-peak and weekend lane-closures on certain Interstate routes.
  • Short-term, moving operations (e.g., striping) on certain Interstate routes.

5.4.1 Process for Requesting Exceptions

The process for exception requests may include the following actions:

  1. Assess the work zone impacts of the specific Interstate project or categories of projects using appropriate methods (qualitative, quantitative, or combination of both).
  2. Compare the expected work zone impacts with the agency's policy provisions and determine whether the project is expected to have sustained work zone impacts.
  3. If the project appears to meet the conditions for an exception, prepare an exception request and submit it to the FHWA Division Office. Blanket exceptions for certain categories of projects that meet certain criteria may be requested on an ongoing basis.
  4. FHWA reviews the exception request.
  5. Take appropriate action based on the results of the review – either reassess the impacts (go back to Step 1) or implement an appropriate TMP based on whether the exception request is approved or not.
    The agency should work with the FHWA Division Office, as appropriate, throughout the process.

5.4.2 Contents of an Exception Request

The contents and degree of detail in an exception request will vary based on the type, complexity, and expected impacts of a project. For projects that are not complex and are of small size or short duration, the exception request may be very simple. For more complicated projects, the exception request may be more detailed yet is not intended to be lengthy. The main element of an exception request will be the agency's assessment of the expected work zone impacts, and may include a description of the project and local conditions.

  1. Hereinafter referred to as agencies.
  2. § 630.1004 of the Rule defines work zone impacts as work zone-induced deviations from the normal range of transportation system safety and mobility. The extent of the work zone impacts may vary based on factors such as, road classification, area type (urban, suburban, and rural), traffic and travel characteristics, type of work being performed, time of day/night, and complexity of the project. These impacts may extend beyond the physical location of the work zone itself, and may occur on the roadway on which the work is being performed, as well as other highway corridors, other modes of transportation, and/or the regional transportation network.
  3. http://www.ops.fhwa.dot.gov/wz/docs/wz-sa-docs/sa_guide_s4.htm

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