5.0 Current TMP Use, Examples, and Practices
This section presents an overview of findings from an investigation of the current use and formats of transportation management plans (TMPs) based on interviews of four State departments of transportation (DOTs) conducted in September and October 2004. The four States interviewed were California, North Carolina, Ohio, and Wisconsin. In addition, background literature reviews on current practices in other States were conducted. Indiana, Maryland, and Washington were States identified through this literature review as having some noteworthy policies, practices, or procedures related to TMP development and implementation.
In general, TMP policies, processes, and requirements are informal and rely mostly on engineering judgment. Each State has some policy provisions for work zone planning and management, but they differ in name, nature, and goal. In Maryland, work zone mitigation efforts are detailed in the Maintenance of Traffic (MOT) reports, which are largely comprised of the work zone temporary traffic control (TTC) plan. The objective of the MOT report is to outline how to maintain traffic for the duration of construction. Indiana Department of Transportation's (INDOT) work zone impact management goal is for an "effective corridor," while California Department of Transportation (Caltrans) Deputy Directive Number 60 (DD 60) concerning work zone impacts strives to "manage delay and safety." Ohio DOT's work zone mitigation policy calls for "Exception Reports" and TMPs whenever lane closure restrictions may be violated by the project, with the priority being "minimizing crashes." Meanwhile, in Wisconsin the main priority is to "reduce construction duration."
Despite these differences in specific goals, each agency is trying to manage work zone impacts and some level of agency pre-construction planning effort exists. For simplicity reasons, mitigation strategy reports developed by the different agencies will be referred to as TMPs, although they might differ from the definition of TMP in the updated work zone Rule (Rule).
Based upon the literature review, most States (other than those interviewed) do not have TMP policies covering major work zone issues typically found during construction, nor do they have guidelines to develop TMPs. Some of the interviewed States do mandate that all construction or maintenance projects must be accompanied by a TMP, which may range from a single-page datasheet to comprehensive reports. The following discussion summarizes some of the processes.
California is one of the few States that has a specific policy on TMPs, and has spent years improving it. In 1993, Caltrans developed their first version of a TMP guidelines document, entitled the TMP Effectiveness Study. Since then, the Office of Operations within Caltrans Headquarters continues to improve upon the guidelines, mainly using past experience. Caltrans focused on improving guidelines on the most effective mitigation strategies in the State of California. The most recent version of California's TMP guidelines was published in June 2001, with addendums on bicycle and pedestrian mitigation strategies added in May 2004.
California policy states, "TMPs, including contingency plans, are required for all construction, maintenance, encroachment permit, planned emergency restoration, locally or specially-funded, or other activities on the State highway system. Where several consecutive or linking projects or activities within a region or corridor create cumulative needs for a TMP, the Department coordinates individual TMPs or develops a single interregional TMP." TMPs are considered early, during the project initiation or planning stage. The project team includes a District Traffic Manager (DTM) or a TMP manager to investigate the level of TMP needed for a project at hand. Caltrans has defined a significant traffic impact as "30 minutes above normal recurring traffic delay on the existing facility or the delay threshold set by the DTM, whichever is less." In California, the level of TMP may fall into three distinct categories:
- TTC Plan only/Blanket TMP. This is typically a one-page datasheet containing information on the proposed construction project, including project description, limits, dates, and duration. Permissible work hours are defined in lane requirement charts.
- Minor TMP. Projects that are considered for minor TMPs typically include those that require additional work zone mitigation measures beyond a TTC plan, such as portable or fixed changeable message signs (CMS) or the California Highway Patrol's (CHP) construction zone enforcement enhancement program (COZEEP).
- Major TMP. For major improvement projects, an extensive TMP that evaluates multiple mitigation strategies, public outreach, and extended closure methods is needed. Major TMPs typically require several months to prepare, and are developed for less than five percent of all construction or maintenance projects at Caltrans.
Ohio Department of Transportation (ODOT) has developed a decision support methodology in determining whether an "Exception Report" (a precursor to TMPs) is required, based on past experience and in-house research efforts. First, the project manager checks the ODOT Permitted Lane Closure (PLC) web application to determine when and how many lanes can be closed on a segment of the freeway. (Every link of the interstate and interstate look-alikes has defined closure times.) If the suggested closure does not violate the PLC, the project may proceed. If the proposal violates the PLC, then a QUEWZ/ODOT spreadsheet analysis of queues is conducted. If for whatever reason the proposal does not meet the PLC and the expected queues exceed the ODOT policy maximums, an exception request is made. The exception request provides numerous alternatives that include discussions on queue impacts, construction costs, and construction schedule. If this report is approved by the Traffic Operations Division at the central office, the full TMP detailing public information strategies, traffic control adjustments, and signing will follow during the detailed engineering phase.
INDOT currently has a TMP development guideline that may be "generally observed" by its practitioners. In Indiana, a TMP is an overall strategy, beyond just a TTC, to accommodate traffic during construction. It is intended to address all project impacts throughout the corridor and region, not just the work zone.
At the start of the preliminary engineering phase, the design team, with input from the district traffic engineers, must decide whether or not a TMP is needed. Once determined, a TMP development team consisting of designers, construction managers, traffic engineers, and stakeholders are formed. The team prepares the TMP in parallel with the development of the preliminary engineering designs. Construction staging and traffic impact issues are considered as one, and in the end, the TMP is incorporated as part of the preliminary engineering report.
During the construction phase, if a significant deviation from the TMP is desired by the construction management team or the contractor, it must be reviewed and approved by the TMP team. For larger projects, a TMP manager is typically appointed to coordinate communications between the TMP and construction teams.
Maryland, North Carolina, and Wisconsin rely on past practice and various design manuals for traffic-related mitigation strategies for work zones. The mitigation documentation must at least include a TTC plan, which is required for all State- and Federally-funded projects.
Indiana, North Carolina, and Wisconsin DOTs believe that in order to develop sound mitigation strategies, the traffic engineers should be an integral part of the design team and consulted during the development of the construction phasing plan. Depending on the complexity of the project, additional issues such as public information, alternate routes, and incident management should also be discussed with the appropriate personnel and stakeholders, as needed. Caltrans also emphasizes this, stressing that the TMP is a dynamic document that is reviewed and modified throughout as necessary. Caltrans considers the DTM and TMP Manager an integral part of the Project Development Team for capital projects.
In other States, the designers often begin the project scoping on their own, developing the construction staging and phasing before sharing the construction plans with the traffic division. In general, the TMP development process starts one or two years in advance of the start of construction, typically during design or preliminary engineering. However, the bulk of the effort is performed on different timelines at different agencies. North Carolina, for example, prefers a simple preliminary analysis far in advance, but does not go into the detailed analysis until three to six months prior to "letting," or the beginning of construction. In California, the districts are encouraged to plan and execute the TMP early for public awareness (one to two years prior to start of construction). Ohio DOT develops MOT scenarios early in project development and uses MOT viability as one of the decision criteria in selecting the project design. The project is designed with the MOT criteria becoming more detailed as the project progresses.
Many agencies, including Caltrans, are making an effort to use more advanced analysis tools such as simulation for work zone impacts assessment. However, simulation costs and time are barriers, since for the types of projects it has been used on it typically costs at least $150,000 and takes several months to collect traffic data and build and calibrate the simulation network. Most agencies rely on conventional analysis, although some California and Wisconsin districts may use QuickZone. Indiana uses QUEWZ to "determine queues and users costs that are associated with work zone lane closures." Ohio incorporated QUEWZ with their own thresholds and default values to determine whether or not an "Exception Report" and TMP are necessary. Additional information on work zone analysis tools can be found in Work Zone Impacts Assessment: An Approach to Assess and Manage Work Zone Safety and Mobility Impacts of Road Projects.
The interviews and the literature review found that in most cases TMPs are developed by the district traffic agencies, under the supervision of a DTM or a TMP manager. Other agencies and/or stakeholders are involved during the TMP development process only if necessary, often serving as sounding boards. While most agencies rely on the DTM (or its equivalent) for engineering judgment, they can also contact their headquarters' office of operations (or its equivalent) for further review and counsel. Smaller districts have few personnel responsible for traffic management, and often they perform dual roles in addition to work zone planning and management.
In California, Washington, and North Carolina, TMPs are typically reviewed only by the DTM or TMP manager, including those developed by consultants. Occasionally, the DTM or TMP manager forwards complex TMPs to the agency headquarters for assistance – this is done on a case-by-case basis. In Ohio, all "Exception Reports" must be submitted to the central office for review – otherwise, no reporting is needed. In Wisconsin, the designers oversee the work of the traffic team on the development of the TMP.
Establishing reasonable performance criteria or thresholds for determining TMP requirements is a policy decision each State has considered. As an example, some agencies have set a maximum additional delay over and above normal operating conditions and use engineering judgment. For example, Caltrans and Wisconsin DOT require that construction or maintenance projects should not increase delay by more than 30 minutes above the normal recurring traffic delay. Interviews with Caltrans traffic operations officials revealed that in practice, this threshold is much stricter, typically set at 15-20 minutes. Any proposed closures that fail to satisfy this threshold require approval from the District Lane Closure Review Committee (DLCRC). The DLCRC decides when to submit lane closure requests that are of an interregional, statewide, environmental, or otherwise sensitive nature to the Headquarters Lane Closure Review Committee for their approval.
Ohio DOT's decision support methodology employs a criterion that a queue length less than 0.75 mile is acceptable. Queues greater than 0.75 mile but less than 1.5 miles are acceptable if the queue exceeds 0.75 mile for less than two hours. Queues longer than 0.75 mile for more than two hours, or longer than 1.5 miles for any period of time, are unacceptable and alternate strategies must be considered.
Engineering judgment is often used in selecting diversion or trip reduction rates. Major construction or maintenance projects, with a reasonable public information campaign, experience some level of trip reduction due to trip cancellations, rescheduling, or significant detours. Many agencies prefer basing their TMPs on the worst-case scenario, where no diversion takes place. In California, if the proposed project results in significant additional delays and queues, the first option is to revisit the construction strategy. If queues and delays continue to exceed the allowable threshold regardless of the staging option, the DTM or TMP manager may take into account the effects of diversion, along with a stronger emphasis on the public information campaign.
The States interviewed tend to rely on prepared templates, past TMPs, and anecdotal information from past projects for the development of TMPs. In Indiana, detailed post-project evaluations are developed as TMP Final Reports, and they contain discussions on the following:
- Overall statement on the usefulness of the TMP.
- Changes to the TMP during construction or implementation.
- Discussion on whether the changes were successful.
- Public reaction to the TMP.
- Average delay, queue length, and number of slowdowns encountered.
- Identification of the peak loading times.
- Frequency of legitimate complaints and their nature.
- Types of crashes that occurred during construction.
- Lessons-learned for future projects.
- Which mitigation strategies were most successful.
California and Ohio also have detailed post-project reviews of the overall project. Included in this are the bid TMP implementation costs, which are archived and can be used for future TMP developments. In addition, California has conducted research focusing on public information strategies, since Caltrans officials believe these are most effective for the cost.
This section describes some of the work zone impact management strategies currently used by the interviewed agencies. The classifications and groupings of the TMP components are those that are typically done by the States. The applicable classifications of TMP components from the updated work zone Rule (i.e., TTC, PI, and TO) have been identified within brackets for informational purposes.
Some common methods used by agencies to reduce traffic in work zone areas are listed below:
- Ramp closures (TTC, TO - Corridor/Network Management). Ohio, North Carolina, and California DOTs have closed on-ramps in the corridor in urban work zones to reduce traffic. Use of this strategy is selective and requires adequate alternate routes and public information.
- Truck restrictions (TO - Corridor/Network Management). Ohio and California DOTs have banned trucks in work zones in cases where there was a need to reduce truck demand and when viable alternate routes exist. This depends on the predicted delay and queue length, and input from the stakeholders.
- Public information (PI). According to Maryland, California, and Wisconsin, public information is the best mitigation strategy that may lead to significant traffic reductions. In rural work zones, Maryland and Wisconsin believe that public information via portable CMS is the best work zone mitigation strategy. Washington DOT has a comprehensive public information program for work zones called "Give 'Em A Brake," with goals of raising public awareness and improving workers' safety.
- Rerouting traffic (TTC - Off-Site Detours, TO). Work zone impact mitigation measures on arterial streets in the affected corridor have been implemented as part of several reconstruction projects, including traffic signal retiming, and intersection and roadway improvements. These measures can facilitate traffic flow even when specific detour routes are not established.
- Transit use and ridesharing (TO - Demand Management). Promoting public transit alternatives is another common work zone mitigation technique for highly urbanized areas with a good transit network. In some cases, services may be expanded temporarily to reduce traffic in the affected corridor.
Lane closure strategies (TTC) vary based on several factors (e.g., functional class, geographic characteristics, scope/type of work, construction techniques, traffic demand, etc.). Lane closures can range from the closure of a single lane up to full closure of the road. In the case of full closures, all the lanes are closed in one or both directions, and the traffic is detoured. Lane closure durations generally can be divided into four categories:
- Daytime off-peak only.
- Nighttime only (10-hour closures).
- Weekend closures (55 to 72 hours).
- Continuous lane closure for the duration of one or more phases or the entire project.
Each State must balance the safety and operational criteria for the specific project when selecting the most effective lane closure strategy. In North Carolina most construction or maintenance work is performed at night, while trying to keep the maximum number of ramps and lanes open. Washington DOT's experience with full closures has been very successful. The approach requires good coordination between the design and traffic operations teams, as well as with local agencies and the public, but can be very effective and efficient.
Wisconsin and California DOTs have flexible lane closure strategies. They use nighttime, off-peak only, weekend, and continuous closure. With the continuous closure, the objective is to reduce the project duration, as well as schedule the project at a time of the year when the traffic volume is typically lower. California is encouraging the use of continuous closures where adequate lead time for public notification is available and the duration is compatible with the proposed construction or maintenance practices.
Most of the interviewed States do not have set procedures to monitor the work zone impacts of projects and the effectiveness of their work zone mitigation strategies. In most cases, work zone and TMP monitoring is the responsibility of the construction manager. However, on projects with greater impacts, there may be a concerted effort to share the responsibility between the DTM and the construction manager, at least during the early stages of construction. Many States rely on the following techniques for monitoring purposes:
- Designated inspectors [TO - Work Zone Safety Management Strategies].
- Windshield surveys [TO - Work Zone Safety Management Strategies].
- Electronic surveillance [TO - Traffic/Incident Management and Enforcement].
- Incident management [TO - Traffic/Incident Management and Enforcement].
Most construction or maintenance projects in California with potentially significant traffic impacts (as defined by Caltrans) have a monitoring program in place, at least during the initial stages of the project. Some districts in California have designated construction traffic managers that can assist in this effort. The Ohio DOT policy requires the project personnel to monitor the queues and compare them against the expected queues generated by the computer model. If the project-generated queues exceed the expected queue lengths, the district must recommend corrective action and the Central Office staff will review the data to determine the cause. The ODOT Central Office and the FHWA conduct field reviews twice a year and watch for safety problems. The Ohio DOT also obtains work zone crash reports (generally within two weeks) and compares them to historical crash trends before the work zone in an effort to identify unexpected problems caused by the work zone and make field changes, as necessary and appropriate.
Most of the States interviewed estimate the costs of TTC/TMP development and implementation as a percentage of the construction project costs. Based on Wisconsin DOT's experience, for example, the development and implementation of a TMP could range approximately from three to five percent of the total construction costs of the project.
TTC development costs of most projects in North Carolina range from approximately a quarter to one-half-percent of the construction costs. North Carolina spends approximately three to five percent of the construction costs to implement the TTC. Approximately $15,000 to $40,000 is spent on typical traffic control designs for about 85 percent of the reconstruction projects in North Carolina. A compilation of projects in the Caltrans' TMP Effectiveness Study indicated that the cost of a TMP ranges from four percent of the construction cost to 30 percent, which amounted to TMP implementation costs ranging from $250,000 to $30 million for these projects. More recent results reported in 2003 show that TMP costs have ranged between one and 15 percent of the total project cost (from $25,000 to $3.35 million).
While still in the process of developing TMP guidelines, Wisconsin DOT has recognized the need for estimating the costs of TMP development and implementation based on road user cost as opposed to a percentage of construction costs. In Maryland, road user costs are not directly used, but the State applies certain strategies to balance between the cost of construction and road user costs, such as contractor bonus/penalty for project timeliness, contractor incentive/disincentive for performance efficiencies, readiness to prepare contract addendums to counter significant problems, or combining several projects into one.
Few States have formal TMP guidelines or policies in place. In most States currently using TMPs, queue or delay threshold criteria and engineering judgment are applied to determine whether a full TMP is required or not. Determining the extent of TMP required, assigning TMP team responsibilities, and estimating TMP development and implementation costs should be done during preliminary engineering or early design. In practice, however the TMP development process often begins only six months prior to the start of construction.
Some lessons learned and comments from the interviews include:
- TMP guidelines should not be restrictive. Project challenges vary greatly from one to another, and these must be identified first before solutions are developed. TMP guidelines should serve as a checklist to consider by practicing agencies.
- Early start. The design team, traffic operations division, and other relevant stakeholders should meet as early as possible, to discuss the project design, staging, and work zone mitigation strategies.
- Determining TMP level. Currently, most agencies rely on engineering judgment, but a "quick-and-dirty" decision support tool similar to the one used in Ohio or another approach may be used to assess TMP needs.
- Clear project scope. Concerning TMP development, implementation, and monitoring, it is imperative to define roles and expectations clearly.
- Road user cost estimation. While most TMPs used today are budgeted as a percentage or a portion of the overall project funding, perhaps actual costs and road user costs should be considered. This is particularly useful for smaller projects with large impacts.
- Mitigation strategy. Public information is considered to be one of the most effective mitigation strategies. It works best in highly urbanized work zones, but still yields effective results in rural areas.
- Balanced focus. Although the main purpose of TMPs is to support road construction projects, work zone transportation management should be considered along with construction issues, not after. Poorly planned construction or maintenance projects may lead to crashes, motorists/worker injuries and fatalities, and/or excessive delays.
- Use of software. Simulation is often used for major projects with significant regional impacts, but simpler queue and delay analysis software to determine the impacts of the project are generally adequate for small to medium range projects.
- Urban areas more tolerant. Urban areas tend to be more tolerant of work zone impacts, since urban commuters are more accustomed to congestion on a daily basis.
- Data may change over time. On many projects, particularly those that have been shelved for some time, project design or traffic volumes may change after the preparation of the plans, specifications, and estimates (PS&E) package. For this reason, Caltrans requires its Project Manager to obtain DTM/TMP Manager signoff right before the project is ready to list, or released for bid, rather than earlier in the process. This helps make sure that traffic volumes are current and that the strategies are compatible with the project design.
The following contains contact information for the individuals interviewed for this section of the document.
California State Department of Transportation
Jacqui Yuke Ghezzi
Chief, Traffic Management Branch, Office of System Management Operations
Phone: (916) 651-9050
Maryland Department of Transportation State Highway Administration
Jawad Paracha, P.E., P.T.O.E.
Traffic Policy & Management Team, Office of Traffic & Safety
Phone: (410) 787-5891
North Carolina Department of Transportation
J. Stuart Bourne, P.E.
Work Zone Traffic Control Engineer
Phone: (919) 250-4159
Steve Kite, P.E.
Work Zone Traffic Control Engineer
Phone: (919) 250-4159
Ohio Department of Transportation
Office of Traffic Engineering
Phone: (614) 466-3601
Wisconsin Department of Transportation
Bureau of Highway Operations
Phone: (608) 266-0982
Table 5.1 provides resource information and web links to some examples of TMPs, TMP-related policies and procedures, and other TMP practices. It also lists references used and literature reviewed related to TMPs.
- California Department of Transportation, Traffic Management Plan Effectiveness Study, prepared by Wilbur Smith Associates, May 1993.
- URL: (Accessed 07/17/05).
- QUEWZ is a program designed for evaluation of freeway work zones but can be used for other highway types. Traffic management approaches for work zones, such as single direction closures and crossovers, can be analyzed.
- The Ohio Department of Transportation (ODOT) Maintenance of Traffic Policy sets allowable queue thresholds. These thresholds are discussed in the Criteria and Thresholds section.
- QuickZone compares the traffic impacts for work zone mitigation strategies and estimates the costs, traffic delays, and potential backups associated with these impacts.
- Available at http://www.ops.fhwa.dot.gov/wz/resources/final_rule.htm
- URL: (Accessed 07/17/05).
- California Department of Transportation, Traffic Management Plan Effectiveness Study, prepared by Wilbur Smith Associates, May 1993.
You will need the Adobe Acrobat Reader to view the PDFs on this page.previous | next