2.0 Work Zone Impacts Assessment Process Example

This section discusses how work zone impacts assessment was conducted for the SR 41 Operational Improvement Project, how decisions were made on what transportation management plan (TMP) strategies to include and implement, and what actions were taken by Caltrans to manage the impacts of the project during construction. The discussion is structured according to the process described in the FHWA guide, "Work Zone Impacts Assessment: A Process To Manage Work Zone Safety and Mobility Impacts of Road Projects"[3] (hereafter referred to as "the FHWA work zone impacts assessment guide").

2.1 Policy

The following provides an overview of Caltrans' policy on work zone impacts mitigation and transportation management. The application of the policy to the SR 41 project is discussed in the respective project development stages that follow this section.

Caltrans Deputy Directive 60 (DD-60)[4] outlines Caltrans' policy on Transportation Management Plans (TMPs) for road projects. The policy is to minimize motorist delays when implementing projects or performing other activities on the State highway system. This is to be accomplished without compromising public or worker safety, or the quality of the work being performed. To achieve these objectives, Caltrans DD-60 requires the development and implementation of TMPs, including contingency plans, for all construction, maintenance, encroachment permit, planned emergency restoration, locally or specially-funded, or other activities on the State highway system.

The following are key concepts in the Caltrans policy:

• A TMP, when implemented, results in minimized project-related traffic delay and accidents by the effective application of traditional traffic mitigation strategies and an innovative combination of public and motorist information, demand management, incident management, system management, alternate route strategies, construction strategies and other strategies. TMPs are to be considered early, during the project initiation or planning stage.
• Significant Traffic Impact is defined as, "30 minutes above normal recurring traffic delay on the existing facility, or the delay threshold set by the District Traffic Manager (DTM), whichever is less."
• Major Lane Closures are those that are expected to result in significant traffic impacts despite the implementation of a TMP. Major Lane Closures require District Lane Closure Review Committee Approval.
• Contingency Plans address specific actions that will be taken to restore traffic flow or minimize effects on traffic when congestion or delays exceed original estimates due to unforeseen events such as work zone accidents, higher than predicted traffic demand, or delayed lane closures.

Caltrans uses three categories of TMPs based on the expected work zone impacts of projects:[5]

• The first category is a "Blanket TMP." This applies to projects where work is done on low volume roads during off peak hours and no delays are expected. It also applies for moving lane closures. A blanket TMP is a generic list of actions that would be taken to keep delay below the delay threshold (as defined above under Significant Traffic Impact) when performing activities on highways. Each district Maintenance and Encroachment Permit office should have a list of activities to which blanket TMPs apply. Typical TMP strategies for such projects include portable Changeable Message Signs (CMS), freeway service patrols (FSP), Traffic Management Team (TMT), and work during off-peak hours.
• The second category is a "Minor TMP." The majority of Caltrans road projects (including this SR 41 example) fall under this category. Generally such projects are intermediate type projects that cause minimal/moderate work zone impacts. They require lane closure charts that specify when and how many lanes may be closed for construction. Additional mitigation measures may be required, such as night work, portable and fixed CMS, construction zone enhanced enforcement program (COZEEP), TMT, highway advisory radio (HAR), FSP, gawk screens, etc.
• The third category is a "Major TMP." About 5% of Caltrans road projects fall under this category. Generally such projects cause significant work zone impacts, and may require multiple TMP strategies and multiple contracts. Typical TMP strategies for such projects include some combination of public awareness campaigns, fixed CMS, extended closures, moveable barriers, COZEEP, detours, reduced lane widths, web site, helicopter traffic reports, etc.

The Caltrans policy outlines specific TMP responsibilities for district staff responsible for planning, designing, and implementing road projects. More information on the specific TMP responsibilities of different staff may be obtained in Caltrans' DD-60.

To help implement the policy, Caltrans provides the following policy guidance, tools, and training to its staff:

• TMP Guidelines;
• Delay Calculation Charts;
• Lane Closure Holiday Restrictions Tables;
• Lane Requirement Charts; and
• TMP-related Training and Outreach.

The Caltrans policy states that TMPs are to be considered early during the project initiation or planning stage, and that they need to be refined and further developed as the project progresses through the various stages of development. This is very similar to the approach discussed in the FHWA work zone impacts assessment guide, wherein work zone impacts assessment and TMP development start from early planning, progressing through preliminary engineering, design, construction, and performance assessment. The following is a list of the stages in Caltrans' project development process, loosely matched against the work zone impacts assessment stages presented in the FHWA work zone impacts assessment guide:

• Identify project need, prepare initiation document, form project development team, prepare project study report, and secure project programming – Systems Planning/Preliminary Engineering.
• Prepare draft project report, perform environmental studies and secure project approval – Preliminary Engineering.
• Obtain approvals; agreements and permits; prepare plans, specifications, and estimates (PS&Es); acquire right of way (ROW); complete project design; prepare and advertise contract – Design.
• Conduct and complete construction project – Construction.
• Project close-out – Construction/Performance Assessment.

The following sections provide an overview of how the SR 41 project team applied Caltrans policy provisions, assessed the work zone impacts of the project, and developed a suitable TMP progressing through the various stages of project development.

2.2 Systems Planning

2.2.1 Caltrans Policy Guidance on TMP Considerations During Systems Planning

Caltrans TMP Guidelines state that TMP development is part of the normal project development process and must be considered in the project initiation document (PID) or the planning stage. This means that the project team needs to assess the potential work zone impacts implications of a project early enough in planning so that they have an understanding of the TMP needs and costs for that project. The extent of a TMP is determined by the District Traffic Manager (DTM) during the preliminary studies of a capital project, namely the Project Study Report (PSR) or Project Study Scoping Report (PSSR). This decision-making on the extent of the TMP is driven by the DTM's understanding of the expected work zone impacts of a project.

Caltrans TMP Guidelines recognize that since projects are generally programmed, budgeted, and given an expenditure authorization upon PSR or PSSR approval, it is important to allow for the proper cost, scope, and scheduling of the TMP activities at this early stage of development. For all TMPs, an itemized estimate of the proposed strategies and their respective costs are included in the PSR for proper funding consideration. The workload required to develop and implement TMPs is estimated in advance and captured in the district work plan. TMPs that are retrofitted to projects already programmed must be handled on a case by case basis and may require a contract change order. More information and specific guidance is available in "Section II. TMP Development and Implementation" of Caltrans' TMP Guidelines,[6] in sub-sections A-C.

2.2.2 SR 41 Project Example – Work Zone Impacts Assessment During Systems Planning

The FHWA work zone impacts assessment guide breaks work zone impacts assessment during systems planning into six steps.[7] The following discussion presents the key work zone impacts assessment activities performed during the systems planning phase of the SR 41 project, organized along those six steps.

Step 1 of 6: Compile Project/Work Zone Scope Information for the Alternatives

Project initiation for the SR 41 Operational Improvement Project came about through Caltrans' knowledge of congestion on the corridor and public complaints on poor traffic flow and delays on SR 41 between Herndon Avenue and Friant Road. This was further confirmed through freeway operational studies conducted in 1999 by the Caltrans Office of Traffic Operations.

As per the Caltrans project development process, a project study report (PSR)[8] was then developed by Caltrans in June 2000 to document the need for the project and develop alternative improvement strategies. The PSR considered four different build alternatives and one no-build alternative in conducting an engineering analysis of current and future traffic flow, delay, and LOS along the corridor. These analyses indicated that the no-build alternative would not work, and that capacity along that section of SR 41 would have to be improved. The PSR identified the details of the specific improvements that would be performed under each of the build alternatives along with cost estimates. From an environmental impact perspective, the PSR identified that the anticipated environmental document for the project would be a Negative Declaration (ND)/Finding of No Significant Impact (FONSI), and that the FHWA and Caltrans would act as lead agencies in the preparation of a joint California Environmental Quality Act (CEQA)/National Environmental Policy Act (NEPA) environmental document to justify the FONSI. The PSR noted that the project would be expected to be in compliance with the Federal Clean Air Act of 1990. The PSR also identified other aspects, including funding and scheduling for the project.

Step 2 of 6: Assess Work Zone Impacts of Alternatives at a Screening-Level

Based on the specific improvements that were identified in Step 1 for the four different alternatives, Caltrans conducted an initial qualitative assessment of the potential work zone impacts of the project (i.e., traffic delay and queuing, ability to perform the work safely, and ability to provide adequate access). This assessment was primarily done by the project/design engineer for the SR 41 project, but consultation was sought from construction and traffic operations personnel as well. This qualitative assessment was based on engineering experience, past experience with similar projects, and an understanding of the traffic conditions along the corridor. Since all the four different build alternatives were very similar in nature, the assessment was conducted for the overall project rather than for individual alternatives.

The results of the assessment were documented in the PSR under the TMP section. The following are the key issues that were addressed and documented:

• TMP Anticipated for Project. It was determined that a specific TMP (rather than a Blanket TMP) would be needed for the project due to potential traffic delays during construction. The PSR did not document how extensive the TMP would be, but Caltrans staff indicated that they had a general idea that the project would need a "Minor TMP." At this stage, there was no determination of specific TMP strategies.
• Potential Construction/Staging and Lane/Ramp Closure Options. The TMP section of the PSR identified high-level construction/staging and lane/ramp closure options. The following is a summary:
  • The project would allow for two through lanes to be available for traffic along northbound SR 41 mainline throughout the length of the project.
  • The median lane would be constructed first, with the aid of temporary railing,[9] i.e., portable concrete barriers (PCBs), shielding the construction work. This could be accomplished by shifting the existing lane configuration to the right and using a reduced 3.35 meter (11 foot) lane width.
  • The second stage of construction would begin with the opening of the median lane. Part of the outside (right-hand side) lane would then be closed for construction work, again shielded by temporary railing (i.e., PCBs).
  • There would be little impact on the traffic using the existing Friant Road off-ramp. Temporary railing (i.e., PCBs) would be placed on the outside shoulder, reducing the shoulder width.
  • Ramp closures would be kept to nighttime only and advance notice would be posted.
  • During the bridge widening construction, four lanes would be provided under the structure at Alluvial Avenue, Nees Avenue, and Friant Road while two lanes would be provided for El Paso Avenue.
  • A lighted pedestrian walkway would be provided under Nees Avenue for the Sugar Pine Trail, to facilitate its use by pedestrians/bicyclists during construction.

Step 3 of 6: Analyze Potential Impacts (Optional)

Because the SR 41 project was a medium-size project expected to have low to moderate work zone impacts, Caltrans did not conduct any quantitative analysis of work zone impacts at this stage.

Step 4 of 6: Identify Potential Work Zone Management Strategies

As part of the initial qualitative assessment (in Step 2), Caltrans identified some of the high-level construction/staging and lane/ramp closure approaches that would be suitable for the project. These approaches, previously discussed in Step 2, were Caltrans' initial thinking on Temporary Traffic Control (TTC) strategies for the SR 41 project. Specific Transportation Operations (TO) or Public Information (PI) strategies were not identified at this stage. The only assertion made was that the project would need a specific TMP.

Step 5 of 6: Perform Plan/Program Level Work Zone Impacts Assessment

This was also done during the initial qualitative assessment (in Step 2) to determine whether the project would have any network/regional impacts and to assess whether there would be any cumulative impacts of multiple projects taking place at the same time along the SR 41 corridor. This was done through consultation with appropriate Caltrans design, construction, and traffic operations personnel. Caltrans determined that the project would not have significant cumulative impacts as a result of other projects in its vicinity.

Step 6 of 6: Compile Planning-Level Work Zone Strategy

Based on the initial qualitative assessments, a planning level work zone strategy was developed for the SR 41 project, and documented in the PSR under the TMP section. This is presented previously in Step 2 of 6. The PSR estimated an annual stream of costs for different aspects of the project including capital costs for Right-of-Way (ROW) and construction; and support costs for project assessments, environmental documentation, PS&E development, ROW support, and construction support. The plan was to design the project in-house, so the support cost estimates were based on Caltrans staff and resource requirements.

The cost estimate also included a high-level estimate of traffic control and management costs. This was based on prior experience with similar sized projects with no specific thumb rules or guidelines used for the cost estimation.

2.3 Preliminary Engineering

2.3.1 Caltrans Policy Guidance on TMP Considerations During Preliminary Engineering

In Caltrans, the preliminary engineering phase is referred to as the Project Report (PR) phase. The transition between systems planning and preliminary engineering is often fluid, without a clear cut distinction between the phases. Therefore, there is generally some overlap between the PSR (developed in systems planning) and the PR (developed in preliminary engineering).

Caltrans TMP guidelines state that as more information becomes available during the project report phase, the preliminary scope and cost of the overall TMP and the individual elements should continue to be refined. The TMP team will coordinate the TMP strategies with the project engineer and appropriate units, with each team member handling their area of expertise. For major projects, subcommittees or task forces may be formed to handle the planning, implementation, monitoring, and evaluation details of some elements. The TMP Manager will keep the Project Manager and District Construction Coordinator updated and must sign-off on the TMP data sheet of the project report. It is appropriate at this point to develop a timeline schedule for major TMPs, keeping in mind that many elements of the TMP have to begin prior to the start of construction. Some tasks may take a long time depending on the complexity of the major project and the type of transportation management necessary. For example, if building new park-and-ride lots is necessary to implement the Ridesharing element of the TMP, the planning phase would have to be extended for several months and a design phase added.

This stage also involves analyzing the existing traffic volume and user mix (e.g. pedestrians, bicyclists, trucks, buses) in the corridor, both on the freeway and surface streets. Such analysis can provide a basis for establishing the goals of the TMP. For example, traffic volume analysis can lead to an understanding of the capacity of the work zone, and the number of vehicles that should be removed from the freeway (through demand management) in order to maintain the work zone traffic demand within its capacity. It can also help identify the capability of the surrounding surface streets to handle any additional vehicular demand diverting from the construction project, and the impact on bicycle and pedestrian traffic. It can also serve as a benchmark for evaluating the overall effectiveness of the TMP in minimizing the work zone impacts of the project. More information and specific guidance is available in Section II. TMP Development and Implementation of Caltrans' TMP Guidelines, under sub-section D, "TMP in Project Report."

2.3.2 SR 41 Project Example – Work Zone Impacts Assessment During Preliminary Engineering

The FHWA work zone impacts assessment guide breaks work zone impacts assessment during preliminary engineering into seven steps.[10] The following discussion presents the key work zone impacts assessment activities performed during the preliminary engineering phase of the SR 41 project, organized along those seven steps.

Step 1 of 7: Compile Project Information

As per the Caltrans project development process, a detailed project report (PR)[11] was developed for the SR 41 Operational Improvement Project. The PR was initiated in June 2001 and completed in January 2002. A freeway operational study of the SR 41 corridor provided key input towards development of the PR. This study analyzed the effectiveness of the different improvement alternatives, and was done in 2001 in cooperation with Professor Dolf May, University of California, Berkeley. The PR outlined the need for the project, the improvement alternatives, the recommendation for the preferred alternative, potential work zone related impacts, other impacts (i.e., environmental, hazardous waste, etc.), other issues to be considered, and programming and cost information. Appendix A of this write-up provides an overview of the key elements that were included in the PR. The project information compiled in the PR was then used by Caltrans to assess the potential work zone impacts of the project and identify the TMP strategies that would be needed.

Note: At the time that the PR was developed, the project had not yet been divided into two phases, and all the assessments were performed assuming that the whole project would be built under one contract. It was further along in the design phase that funding constraints led to the splitting of the project into two separate contracts. This aspect is discussed in the Design discussion (Section 2.4) that follows this section.

Step 2 of 7: Reassess Project Definition

While developing the PR, Caltrans identified a preferred alternative for the project and included that as a recommendation in the PR. The preferred alternative discussion included a description of the exact nature of the work to be done, the construction strategies, cost, potential impacts, and other information relevant to the project.

The following issues were identified as part of the reassessment of the project definition:

• Future Use of Construction Staging Lane. To handle stage construction traffic, the preferred alternative proposed to construct a northbound traffic lane in the median of SR 41 from El Paso Avenue to just north of Friant Road. This median lane would then accommodate traffic during the construction of the two auxiliary lanes to be built as part of the project (i.e., the first auxiliary lane from Herndon Avenue to Friant Road, and the second auxiliary lane from Alluvial Avenue to Friant Road). After completion of construction, this median lane would be delineated as a wide inside shoulder that could possibly be converted to a traffic lane in the future (if needed).
• Utilities. The PR contained a ROW data sheet that identified various utilities located along the project limits. All of the utilities crossed the state facility at local road crossings (Alluvial Avenue, Nees Avenue, etc.), and therefore, the PR stated that no utility relocations were expected.
• Tree Planting. The PR proposed a separate planting project following this highway construction contract. The planting project would contain replacement planting as well as new planting.
• Erosion Control. The PR identified that the SR 41 project would require erosion control since earthwork operations were involved and water quality discharge requirements were to be maintained.
• Impacts on the Sugar Pine Trail. The PR identified that the Sugar Pine Trail would be impacted during construction, but no temporary or permanent adverse effects would result. This facility is a pedestrian/bicycle trail and provisions were established to preserve the safe and convenient movement of bicycle travel through the construction site.
• Right of Way Data (ROW) Sheet. The ROW data sheet documented utility locations, necessary land acquisition and costs, and other ROW information.
• Construction Cost Estimate. The PR estimated a construction cost estimate of $12,547,000 for the preferred alternative, including construction, structures, and ROW costs.

Step 3 of 7: Develop Candidate Construction Approaches

Based on information available on the project, the Caltrans project team identified and developed appropriate construction approaches for the project while developing the PR. This was done primarily by the design/project engineers, in consultation with construction, traffic operations, and other necessary technical experts (e.g., hydraulics engineers).

The identified construction approaches were then documented in the PR as follows:

• Staged construction would be provided in order to minimize impacts to the traveling public. Two through lanes would be provided on SR 41 during construction for the entire duration of the project.
• Two construction stages were identified, along with specific traffic handling (i.e., TTC) strategies for each stage.
  • Stage 1 would construct a traffic lane in the median of SR 41 from the El Paso Avenue under-crossing to just north of the Friant Road under-crossing. Traffic handling would consist of placing temporary barrier railing along the left edge of traveled way and having reduced lane and shoulder widths. Retaining wall construction would begin in Stage 1 to allow placement of the auxiliary lanes in Stage 2. Stage 1 would also include widening the northbound off ramp to Friant Road, for which, the outside ramp shoulder would be closed and temporary barrier railing placed on it.
  • Stage 2 would construct the two auxiliary lanes to be built as part of the project (i.e., the first auxiliary lane from Herndon Avenue to Friant Road, and the second auxiliary lane from Alluvial Avenue to Friant Road). Traffic handling for Stage 2 would consist of placing temporary barrier railing along the right edge of traveled way and shifting the traffic lanes to the left. Two traffic lanes would remain open with a reduced outside shoulder width.
• After completion of the two auxiliary lanes, the median lane to be constructed as part of Stage 1 (from El Paso Avenue to Friant Road) would be converted to a wide inside shoulder, which could be converted to a traffic lane in the future (if needed).

Step 4 of 7: Perform Preliminary Work Zone Impact Assessment

Based on available project information, Caltrans initiated a more focused examination of the potential work zone impacts of the SR 41 project. Though the PSR (developed in systems planning) identified that a TMP would be needed for the project, it did not identify specific TMP strategies. At this stage, Caltrans conducted more focused assessments to identify potential traffic delay and queues as a result of the project, and to identify TMP strategies that would be needed to manage those impacts. These assessments were conducted by the design/project engineers with consultation from construction, traffic operations, maintenance, and other personnel. The assessments indicated the following:

• Lane closure charts would be needed to determine the construction hours (i.e., time of day and days of the week when construction could be done, when lanes might be closed on the mainline, the number of lanes that might be closed, ramp closure times).
• A TMP checklist would be needed to identify specific TMP strategies and estimate their costs.

Step 5 of 7: Analyze Potential Impacts (Optional)

As a follow-on to the preliminary assessment (in Step 4), Caltrans proceeded to do additional analysis to determine the potential traffic delays and queues due to the project, and establish lane closure specifications, and complete the TMP checklist to identify specific TMP strategies. This analysis was done mainly by traffic operations staff, who then provided recommendations to the design and construction staff.

The activities performed for the SR 41 project were a Preliminary Lane Closure Analysis and Compilation of a Preliminary TMP Checklist.

Preliminary Lane Closure Analysis. This analysis was conducted by examining traffic volumes on the SR 41 corridor and the ability of the work zone to handle that demand given various lane-closure scenarios (i.e., number of lanes closed, closure duration, closure length). Caltrans has a master template for the different state routes in the district that define the performance requirements for those corridors. Working from this master template, Caltrans applied Highway Capacity Manual (HCM) capacity reduction factors for construction related lane closures, to evaluate the potential delay impacts of various lane closure scenarios.[12] For example, Caltrans assessed whether 1-lane could be closed or 2-lanes could be closed, and at what times of day the lanes could be closed without significantly affecting traffic flow and delay. Based on this preliminary analysis, Caltrans developed the following lane closure requirements:

• For work on the two-lane section of SR 41 between El Paso Avenue and Friant Road, lanes could only be closed at night time hours without significantly impacting traffic flow. Lane closures during the day would likely result in traffic delays exceeding the Caltrans threshold of no more than 30 minutes above normal recurring traffic delay on SR 41. A preliminary Lane Closure Chart (LCC) was prepared for this section. The following lane-closure times were specified in the LCC for this section:
  • Monday through Thursday, lane closures would allowed only between 9 PM to 6 AM.
  • On Fridays, lane closures would be allowed only between 10 PM to 6 AM.
  • On Saturdays, lane closures would be allowed only between 8 PM to 9 AM, and on Sundays from 8 PM to 10 AM.
  • The LCC also specified that in each of these cases, at least one paved traffic lane must be available for vehicles.
• For work on the three-lane section of SR 41 between Herndon Avenue and El Paso Avenue, the preliminary analysis indicated that in addition to night times specified above, work could also be done during daytime hours, provided at least two paved traffic lanes were available for motorists. However, day time work would not be allowed during the weekday afternoon peak period between 4 PM - 7 PM.
• For work on the SR 41 ramps at Herndon Avenue and Friant Road, preliminary Ramp Closure Charts (RCC) were developed. These indicated that ramp-closures would be permitted only during nighttime hours as follows:
  • Monday through Thursday, from 9 PM to 6 AM.
  • Friday, from 10 PM to 6 AM.
  • Saturday from 8 PM to 9 AM.
  • Sunday from 8 PM to 10 AM.

The preliminary LCCs and RCCs prepared at this stage would then be used as a basis for further analysis during design to develop the final LCCs and RCCs for the project. Note that, at this stage the project had not yet been divided into two phases, and all the assessments were performed assuming that the whole project would be built under one contract. This is why there were different LCCs developed for the two-lane and three-lane sections of SR 41 within the project corridor. For the sake of brevity, the preliminary LCCs and RCCs are not included, only the final LCCs and RCCs are included in the Design discussion in Section 2.4.2.

Compilation of Preliminary TMP Checklist. Based on the lane-closure analysis and other information obtained from the previous steps, Caltrans compiled a Preliminary TMP checklist for the project. The checklist served as the basis for further design and development, and was refined, updated, and finalized during the design phase. The details of the TMP checklist are discussed in Step 6.

Step 6 of 7: Identify Preliminary Work Zone Management Strategies

Based on the activities conducted in the previous step, a Preliminary TMP checklist was compiled. The checklist indicated that no construction strategies could maintain the existing number of lanes for the project.[13] No delay calculation was done at this stage. The following preliminary TMP elements were identified at an estimated cost of $202,000:

• Public Information;
• Motorist Information Strategies;
• Incident Management;
• Construction Strategies; and
• Demand Management.

The Preliminary TMP Checklist is included in Appendix B. It includes the specific elements comprising each of the TMP strategies along with their cost estimates.

Step 7 of 7: Compile Preliminary Work Zone Strategy

Based on the assessments from the previous steps, the preliminary work zone strategy was compiled and included in the PR at appropriate locations. The following is a summary of the key work zone strategy aspects documented in the PR:

• Due to the potential for traffic delays during construction, the PR noted that every effort would be made to inform motorists.
• Construction sequences that would affect traffic operations would be made public so that alternate routes could be taken. The media would be used to keep the traveling public informed of construction progress, information pertaining to delays, closures, and major changes in traffic patterns.
• As part of incident management, the Construction Zone Enhanced Enforcement Program (COZEEP)[14] would be used.
• Nighttime work was recommended for the project to limit traffic disruptions.
• A majority of the construction work could be done behind temporary barriers and without lane closures. When required, the northbound off ramp to Friant Road would be closed only during nighttime hours or weekends with advance notice posted. The northbound on ramp from westbound Herndon Avenue might be closed for an extended amount of time, and traffic might be diverted to use the northbound on ramp from eastbound Herndon Avenue or the two northbound on ramps from Friant Road.
• The PR also documented other issues such as ROW, utilities, environmental issues, and impacts on a nearby trail. All these are summarized in Appendix A of this write-up.

2.4 Design

2.4.1 Caltrans Policy Guidance on TMP Considerations during Design

Caltrans' TMP guidance states that the TMP and other traffic handling components will be finalized during design. Specific guidance is provided on how to include the TMP components in PS&Es, for example, distinguishing between State Furnished Materials and Expenses versus those that need to be covered by the contractor. The guidance also addresses including appropriate "Maintaining Traffic" Standard Special Provisions (SSP) and requiring contingency plans in the SSPs. More information and specific guidance is available in Section II. TMP Development and Implementation of Caltrans' TMP Guidelines, under sub-section E, "TMP in PS&E."

2.4.2 SR 41 Project Example – Work Zone Impacts Assessment During Design

The FHWA work zone impacts assessment guide breaks work zone impacts assessment during design into five steps.[15] The following discussion presents the key work zone impacts assessment activities performed during the design phase of the SR 41 project, organized along those five steps.

Step 1 of 5: Compile Preliminary Engineering Material

Subsequent to completion of the PR in January 2002, some of the funding for the project was lost. A meeting was held in January 2003 with Caltrans staff from the Divisions of Transportation Planning, Project Development, Project Management, and the Offices of Traffic Operations and Traffic Engineering. A discussion took place to determine what original design features should be built with the available construction capital. The participants agreed that the reduced project had to be consistent with the ultimate concept of the original project, and that the proposed work must improve the quality of traffic flow along NB SR 41 and the NB off ramp to Friant Road, by reducing spot congestion and operational deficiencies. From this discussion, an alternative emerged that met this requirement and allowed for future work that could complete the original proposed project. An alternative was then developed which was a reduced version of the Preferred Alternative described in the PR. This information was then documented in a supplemented project report in June 2003.[16]

Based on the information from the PR and the supplemental PR, the project team developed the final design for the project and developed detailed plans for staged construction.

Step 2 of 5: Reassess Work Zone Impacts

The project team then qualitatively reassessed the potential work zone impacts (i.e., work zone related traffic delays, queues, access issues, and safety issues) of the project through consultation with appropriate staff from design, construction, traffic operations, maintenance, and other specialty areas. This reassessment focused only on the first phase of the overall project, which would be built as part of the contract to be let in the summer of 2004. The reassessment indicated that in general, the traffic delay and queuing would be within what was estimated during preliminary engineering, and in fact would be lower because only the first phase was to be constructed.

Step 3 of 5: Analyze Work Zone Impacts (As Needed)

The project team then quantitatively analyzed the traffic delay and queues that may be expected during construction. This included lane closure analysis, Road User Cost (RUC) analysis, and development of a TMP checklist. The LCCs/RCCs and preliminary TMP checklist developed in preliminary engineering were used as a starting point for conducting the analysis. The following is an overview of the analyses activities that were performed during design.

Finalization of Lane Closure Charts. As discussed before, Caltrans policy provides specific guidance on when lanes may be closed on different types of roadways in the form of lane-closure charts. The preliminary LCCs/RCCs (from the PR) set the basic requirement that lane/ramp closures would be permitted only during nighttime hours for the section of SR 41 from Alluvial Avenue to Friant Road (the section that was constructed in Phase 1 of the project). Using this as a base, final lane-closure charts were prepared using traffic volume analyses, assuming that lane closures would be permitted only at night time, with at least one-lane being open to traffic during that time. Using the HCM capacity reduction factors for work zones, the single-lane capacity of the SR 41 corridor was estimated at 1131 vehicles per hour (vph). This was then compared against the hourly traffic demand for weekdays (Monday through Thursday), Fridays, Saturdays, and Sundays. This comparison is shown in Figure 2.

Figure 2. Traffic Volume Analysis Used for Lane-Closure Chart Preparation for Mainline SR 41

In the above figure, the estimated single lane capacity is shown as a blue bar with dots, the weekday (Monday – Thursday) traffic demand is shown in green, the Friday traffic demand is shown in yellow, the Saturday traffic demand is shown in light blue, and the Sunday traffic demand is shown in blue. The time-stamps shown along the X-axis represent the end of an hour period. For example, the data shown at the 6:00 AM time-stamp represents the 5 AM to 6 AM hourly period. Caltrans made the following inferences from this data:

• On weekdays (Monday – Thursday), the hourly traffic demand would be higher than the estimated single lane capacity from 6 AM to 9 PM. The demand would be lower than capacity between 9 PM and 6 AM.
• On Fridays, the hourly traffic demand would generally be higher than the estimated single lane capacity between 6 AM and 9 PM. The demand would generally be lower than capacity between 9 PM and 6 AM, with the exception that from 9 PM to 10 PM, the demand would be slightly higher than capacity.
• On Saturdays and Sunday, the hourly traffic demand would generally be higher than the estimated single lane capacity between 9 AM and 8 PM. The demand would be generally lower than capacity between 8 PM and 9 AM, with the exception that from 8 PM to 9 PM on Saturdays the demand would be slightly higher than capacity.

This information was then used by Caltrans to develop the final LCCs and RCCs. The times when traffic demand would generally be lower than the estimated single lane capacity were identified for construction. In cases where the demand was slightly higher than capacity (i.e., 9 PM – 10 PM on Fridays, and 8 PM – 9 PM on Saturdays), Caltrans engineers used their judgment to decide that there would be no significant traffic delays. Separate lane-closure charts were prepared for different aspects of the construction including survey work, mainline lane closures, and ramp closures. Figure 3 presents the final LCC used for mainline SR 41 construction.

Figure 3. Final Lane-Closure Chart Used for Mainline SR 41 Construction

Since the traffic volume analysis (Figure 2) indicated that daytime work was not possible, the LCC shown above specifies that on weekdays, lane closures would only be allowed between 9 PM and 6 AM, and on weekends between 8 PM and 9 AM, with at least one lane of through traffic being open during construction at those times. Figure 4 presents the final RCC used for ramp closures at the northbound SR 41 off-ramp to Friant Road. It shows that on weekdays the ramp may be closed from 9 PM to 6 AM, on Saturdays from 8 PM to 9 AM, and on Sundays from 8 PM to 10 AM.

Figure 4. Final Ramp-Closure Chart Used for the NB SR 41 Off-Ramp to Friant Road

Performance of Road User Cost (RUC) Analysis. Caltrans requires RUC analysis for all projects $5 Million and higher. Therefore RUC analysis was conducted to determine if the SR 41 project qualified for A+B type bidding. RUC was calculated for an average weekday (between Monday and Thursday) using a Caltrans spreadsheet model. This model uses work zone volume, work zone related delay, queue related delay, and detour related delay to estimate the RUC. The following provides a brief overview of the RUC analysis:

• RUC = f (Work Zone Delay + Queue Delay + Detour Delay)
• Work zone delay is the added time to travel the work zone at a speed lower than that of unrestricted flow. For the SR 41 project, the work zone speed for cars was estimated at 50 mph (as compared to 65 mph unrestricted), and that for trucks was estimated at 40 mph (as compared to 55 mph unrestricted). As a result, the added time to travel the 0.60 mile work zone was estimated as 0.003 hours per car and 0.004 hours per truck.
• Queue Delay is the added time to travel the work zone as a result of work zone induced queues. For the SR 41 project, work zone capacity analysis was used to estimate potential work zone queuing. This is shown in Figure 5. As shown in the figure, construction was expected to take place between 9 PM and 6 AM, when one lane would be open to traffic, with an estimated capacity of 1,311 vph. However, the traffic demand during those times would always be lower than capacity, ranging from a low of 86 vph from 3 AM - 4 PM, to a high of 1,156 vph from 9 PM - 10 PM. As a result, the queuing rate would always be a negative rate, that is, there would be no queues as a result of the construction project. For example, even during the highest work zone demand period from 9 PM to 10 PM, the rate of queue formation would be –155 vph. Therefore, no queues would form and no delays would result.
• Detour Delay applies to vehicles that take a detour to avoid work zone queues, and represents the added time for those vehicles to travel the detour as compared to traveling their original route. For the SR 41 project, since no work zone related queuing was expected, no vehicles were expected to take the detour. Therefore, the detour delay would also be zero. This analysis is also shown in Figure 5.

Figure 5. Work Zone Traffic Analysis for Queue and Detour Delay Estimation for an Average Weekday

As explained above, since the queue delay and detour delay would be zero for the SR 41 project, the only contributing factor to the RUC calculation would be work zone delay. The work zone delay per vehicle (i.e., 0.003 hours per car and 0.004 hours per truck) was multiplied by the total number of vehicles traveling the work zone to obtain total work zone delay. Figure 5 shows the number of vehicles traveling the work zone as 3,413 vehicles. This volume was divided into cars and trucks by using estimated percentages for cars (94 percent) and trucks (6 percent), and used to calculate total work zone delay for all cars and trucks that would travel the work zone. The total work zone delay was then multiplied by the respective hourly RUC rates for cars ($9.00) and trucks ($24.00) to give an estimated RUC of $106 per day for the SR 41 project. However, in order to account for potential inconsistencies in traffic volumes, variations in work zone conditions and other factors, Caltrans recommends that the estimated value of RUC be reduced by 50 percent. Therefore, the final RUC for the SR 41 project was set at $53 per day.

The calculated RUC value of $53 per day was consistent with the fact that the project would be built entirely at night when the traffic volumes would be low, and delays would be negligible. According to the Caltrans policy, the SR 41 project did not qualify for A + B consideration since the daily calculated road user cost was far below the minimum required road user cost of $5,000 per day.

Step 4 of 5: Develop/Recommend Final Construction Staging and TMP

The final TMP was finalized in 2003 during design, after the construction staging, traffic handling, and detour plans were finalized. In finalizing these elements, the design/project engineers consulted with traffic operations and construction personnel to ensure viability of their decisions in the field.

The following activities were performed at this point:

• Development of Final TMP. The final TMP was developed based on the information prepared during earlier stages and during design. The TMP report provided an overview of the project and the specific construction activities that constituted the project. It then provided a listing of specific TMP strategies to be included, along with implementation details and cost estimates. The chosen TMP strategies included Public Information/Public Awareness Campaign, Motorist Information Strategies, Incident Management, and Construction Strategies. Since the project was split into two separate contracts, the total cost of the TMP for this first phase was estimated at $ 70,000 (as opposed to the $ 202,000 estimated for the whole project in the preliminary TMP).
  
  The following excerpts from the TMP report provide specific details about the individual TMP strategies, while Appendix C of this write-up provides details on the individual elements that comprised each of the strategies:
  • Public Information: The TMP report stated that public information was a vital component of the TMP, and that the objective of the public information campaign was to disseminate timely information related to construction activities. The scope of the campaign included informing the public about the construction project and its impacts on the communities, and providing information on various measures commuters might use to avoid anticipated congestion, particularly during peak periods. The responsibility of making the project information available to all applicable entities would be held by the Caltrans' Public Information Office with information provided by the Resident Engineer through the District 6 Transportation Management Center (TMC). The report also identified that the project's Resident Engineer must keep the District 6 TMC well informed and up-to-date on the construction progress, delays, closures, and other information which might assist them in the performance of their duties. The estimated cost of this Public Information/Awareness Campaign was $10,000.
  • Motorist Information Strategies. The TMP report noted that the Motorist Information System to be implemented during construction would be as critical as the public information campaign. The main component of this system would be Changeable Message Signs (CMS) to provide real time traffic information to motorists approaching the construction zone. This information would guide and assist the motorists in making alternate route selections to avoid the impacted area. An extensive signing scheme would be developed to encourage voluntary diversion away from these impacted areas and to guide motorists through the various alternate routes. The TMP report noted that fixed (pre-existing) and portable CMSs would be used for the project. The cost of the motorist information strategies was estimated at $40,000.
  • Incident Management. The final TMP report stated that on highways under construction, incidents and/or vehicular breakdowns can compound an already adverse traveling condition. The report further added that to minimize the impacts of such events, the TMP incorporated incident management elements. Such elements, either on site or close at hand, were intended to reduce the effects of incidents or vehicular breakdowns on the flow of traffic. COZEEP was the key incident management element that was identified in the TMP, at an estimated cost of $20,000, based on the standard unit hourly cost of $55 per officer.
  • Construction Strategies. The final TMP report noted that construction strategies would be needed for the project. These were defined as TMP measures specified in the plans and specifications to be performed by the contractor during construction. The objectives of the construction strategies were to reduce construction time, minimize traffic disruptions, and avoid potential safety problems during construction. Key construction strategies included lane/ramp closure charts, extended weekend closures, ramp closures, and reduced speed zones. Since these strategies were design strategies that were incorporated in the design for the project, there was no specific cost attributed to them.
    
    The final TMP report also identified that further traffic management measures might be implemented, should unusual and unplanned circumstances warrant them. These would be determined on an individual, day-to-day basis. The District 6 TMC, in conjunction with the Offices of Maintenance and Construction, would continuously monitor the project to ensure the safe and efficient movement of traffic. All changes or modifications were to be coordinated through the Office of Traffic Operations except in those instances where any delay could cause a degradation of the system or public safety, in which case, TMP changes or modifications might be implemented without coordination with the Office of Traffic Operations. All costs of implementing the transportation management plan, including its preparation, would be borne by the project. The total estimated cost for all TMP strategies was $70,000.
• Finalization of TMP Checklist. A final TMP checklist was developed during design. A copy of the final TMP checklist is included in this write-up in Appendix D. The following is a list of issues included in the TMP Checklist:
  • Project overview and description.
  • Facility type.
  • List of construction strategies that could help maintain the existing number of lanes.[17]
  • Calculated Delay (to be performed only if the construction strategies listed above do not mitigate congestion resulting from the project, or on all projects along Interstate 5 and Route 99).
  • TMP Elements and Cost (identified all elements and estimated costs that would be used to mitigate congestion resulting from the proposed construction activities, along with assumptions and special instructions).
• Final Design, PS&Es, Construction Staging Plans, Traffic Handling Plans, and Detour Plans. The final PS&Es and plans were developed based on all the previously conducted analyses, and included traffic handling plans (TTC plan) and detour plans for ramp and local road closures.

Step 5 of 5: Advertise and Award Contract

Caltrans advertised and awarded the contract as a low-bid contract. Construction started in August 2004 and was completed in May 2006.

2.5 Construction

2.5.1 Caltrans Policy Guidance on TMP Considerations during Construction

Caltrans TMP guidance states that during construction, TMP elements must be monitored carefully for proper functioning and for cost effectiveness. The guidance also addresses the enforcement and administration of the contractor's compliance with lane closure requirements and provides delay penalty thresholds for transgressions. It also addresses the issue of terminating lane closures if traffic impacts become significant either due to a project incident or activities outside the project area. The guidance specifically states that in order to avoid significant traffic impacts, it is essential to monitor and respond immediately to delay, pick up closures on time, and have solid traffic and contractor contingency plans. A Caltrans staff member who can make informed decisions about implementing contingency plans and modifying, terminating, or extending approved lane closures should be available to respond to significant delays and other unexpected events whenever lane closures are in place. The designated employee(s) may be Traffic Operations, Construction, or TMC staff, depending on the organization of different Caltrans Districts. Another topic that is addressed is Contingency Plans for all planned work. More information and specific guidance is available in Section II. TMP Development and Implementation of Caltrans' TMP Guidelines, under sub-section G, "TMP during Construction and Maintenance Operations."

2.5.2 SR 41 Project Example – Work Zone Impacts Assessment During Construction

The FHWA work zone impacts assessment guide breaks work zone impacts management during construction into seven steps.[18] The following discussion presents the key activities performed during the construction phase of the SR 41 project, organized along those seven steps.

Step 1 of 7: Coordinate Pre-Construction Activities

A kick-off meeting was conducted as part of pre-construction coordination for the SR 41 project. In addition to the project team and the contractor, this meeting was attended by representatives of all Caltrans (District 6) functional units that were involved in the project. These included representatives from design, construction, traffic operations, maintenance, and hydraulics. The City of Fresno and other stakeholders were not part of this meeting, because at the time of pre-construction coordination there were no specific issues that impacted the City of Fresno and other stakeholders.

Step 2 of 7: Review Contractor's Alternate Approach (As Needed)

The PS&Es for the SR 41 project specified that the project would be constructed in two separate stages, with Stage 1 consisting of three sequential parts. During pre-construction coordination, the contractor proposed to combine two parts of the first stage and build them concurrently to save time and for ease of construction. The alternate approach proposed by the contractor did not require any re-design or change orders. A "pre-job review" was conducted by the different Caltrans functional units and the contractor to assess the practicality and viability of the proposal, and it was approved. The contractor did not submit any Value Engineering or Partnering proposal.

Step 3 of 7: Reassess Anticipated Work Zone Impacts (Revise TMP, if necessary)

During the pre-job review of the contractor's alternate staging approach, an assessment was done to identify if simultaneous construction of both stages would lead to additional work zone impacts or require modifications to the TMP. This review was performed qualitatively, and no apparent issues were identified and no additional quantitative analysis was needed. Therefore, no changes were made to the project layout, design, traffic handling plan, or TMP. A major reason for this was because the project was scheduled to be built at night, avoiding all day time and peak periods of traffic.

Step 4 of 7: Implement TMP

The following are some of the key aspects related to the TMP implementation for the SR 41 project:

• Since the TMP was minor it was not necessary to initiate any of the TMP elements prior to construction.
• Though money was allocated for COZEEP, the project's Resident Engineer (RE) and others decided not to use COZEEP. Use of COZEEP is the discretion of the RE and he did not see the need for COZEEP on this project because:
  • The project extent was fairly short, about 0.6 miles;
  • The project was constructed entirely at night when overall traffic volume was very light;
  • Nighttime truck traffic on the corridor was insignificant as shown in the traffic volume analysis in Figure 2; and
  • The project utilized positive separation in the form of PCBs (referred to as temporary railing or k-rail in Caltrans), with all the work being done behind the PCBs.
• As part of the public awareness/information component of the TMP, ongoing coordination was performed to inform the public of upcoming night-time lane closures on mainline SR 41. This was done using Caltrans' electronic Lane Closure System (LCS), an Internet based system developed by Caltrans Headquarters and used statewide for coordinating construction lane closures. Caltrans guidelines require that the public be informed of upcoming lane closures at least 1-week prior to implementation. The project's RE submitted lane closure requests to the District-6 TMC for approval. Upon approval, the TMC sent the information to the District-6 Public Information Officer (PIO), who then released the information to the media, including newspapers, television and radio networks, and websites as appropriate. Upcoming mainline lane closure information was also displayed (starting 1-week prior to implementation) on the permanent CMSs operated by the District-6 TMC.
• Ongoing coordination was performed with the City of Fresno to inform them about upcoming ramp and local road closures. This coordination was relatively easy because the design engineers had already worked with the City of Fresno during the design phase to identify issues and establish the necessary ground rules for minimizing the impacts of ramp and local road closures. Portable CMSs were used on local roads (1-week ahead of implementation) to inform the public about upcoming ramp and road closures.
• Weekly project team meetings (attended by Caltrans personnel and contractor staff) were conducted at the construction site. These were usually conducted before any work was done for the week. Issues that were discussed and addressed included work schedule, plan of action for the week, worker safety, safety of the construction operation, and traffic safety.

Step 5 of 7: Monitor Work Zone Safety and Mobility Impacts During Construction

The following are the key monitoring and management activities that were performed during the SR 41 project construction phase:

• Monitoring and Enforcement of Contractor's Performance. Caltrans adopted an informal approach to ensure that the contractor adhered to the traffic maintenance and TMP requirements. This was done through enforcement of the PS&Es, the special provisions, and particularly the lane closure charts. No penalties were levied upon the contractor because there was no need to extend the lane closure hours beyond what was specified in the lane closure charts.
• Work Zone Safety and Mobility Monitoring. Regular construction safety inspections were performed by Construction Inspectors (CIs). CIs mainly focus on safety inspections but it is also their responsibility to monitor traffic delays. On larger projects, CIs drive along with the back of the queue to the end of the construction zone and clock the delay time. Because the SR 41 project was a medium-size project and the expected delays were insignificant, delay monitoring was done through visual observation only. The project did not lead to any significant mainline traffic delays because all the work was done at night, and at any point the delay did not exceed the allowable 30-minute threshold for freeways. Delay monitoring was also done on local streets that served as detour routes. The SR 41 detours worked well and no significant delays were observed.
• Emergency/Incident Monitoring and Management. No emergency situations were encountered that necessitated corrective actions to modify the TMP implementation. There were a few crashes, but not significant enough to affect the construction activities or the traffic safety and mobility through the work zone.
• Public Feedback. There were no special efforts undertaken to solicit public feedback but a project telephone number was established for the public to call with inquiries or feedback. Any information provided through the phone line was received by the District-6 and PIO and in turn relayed to the appropriate functional units associated with the project. No negative feedback was received from the public on the SR 41 project, and therefore, there was no need for any corrective action.

Step 6 of 7: Assess Compliance with Performance Criteria

Caltrans policy stipulates a 30-minute traffic delay threshold for freeways during construction. Since the SR 41 project was constructed at night, traffic delays were almost non-existent, and visual observations indicated that any delay was well below the 30-minute threshold. Caltrans does not stipulate any policy guidance on safety performance, but there were only a few minor accidents during the course of the SR 41 project.

Step 7 of 7: Document Work Zone Performance Findings

The construction approach and the TMP for the SR 41 project seemed to work very well, and there were no notable safety or mobility impacts. Therefore, Caltrans did not necessarily document any of the work zone performance findings.

2.6 Performance Assessment

2.6.1 Caltrans Policy Guidance on Performance Assessment

Caltrans TMP guidelines require a post-TMP evaluation report to be completed by the TMP Manager at the end of the project for all major TMPs, and for TMPs where the actual delay exceeded the threshold set by the DTM. Post-TMP meetings with the CHP and other partners can be held to identify what went well and what could have been done differently. Samples of past TMP reports can be obtained from headquarters' Traffic Operations, Office of System Management Operations, and from the DTM.

More information and specific guidance on the post-TMP evaluation report is available in Section II. TMP Development and Implementation of Caltrans' TMP Guidelines, under sub-section G, "TMP during Construction and Maintenance Operations."

2.6.2 SR 41 Project Example – Performance Assessment Discussion

Caltrans did not develop a post-TMP evaluation report for the SR 41 project because of the following reasons:

• The project used a minor TMP.
• The project was constructed at night when the traffic volume was very low. As a result, there were no significant construction related traffic delays and no major mobility problems were experienced during TMP implementation.
• Positive protection was used between the work area and the traveled lanes, and all the work took place behind PCBs. There were no major incidents or safety related issues during TMP implementation.

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