Project Design
Project designers, working in concert with other functional experts, should consider maintenance of traffic during construction early in the design process. Designers should examine the use of different project execution strategies that can accelerate construction time and minimize the exposure of travelers to work zones. In addition, designers should actively lead the preparation of Transportation Management Plans, including Traffic Control Plans that will mitigate the impact of work zone activities.
Figure 4 shows the average rating by question for 2005 and 2006 for the Project Design section. Table 7 shows the actual values along with the percent change in average rating from 2005 to 2006 for each question. The average ratings increased from 2005 to 2006 for most of the questions, and items 11 and 12 in this section (both related to processes for developing traffic control plans) experienced relatively large increases. Two items - Item 3 (the use of multidisciplinary teams for developing TMPs) and Item 4 (constructability reviews) - experienced modest decreases.
Figure 4. Results for Project Design Section
| Section | 2006 | 2005 | Change | % Change |
|---|---|---|---|---|
4.3.1 |
8.6 |
8.4 |
0.1 |
1% |
4.3.2 |
8.4 |
8.7 |
-0.2 |
-3% |
4.3.3 |
9.1 |
9.5 |
-0.4 |
-4% |
4.3.4 |
10.4 |
10.0 |
0.3 |
3% |
4.3.5 |
6.7 |
6.4 |
0.3 |
4% |
4.3.6 |
9.3 |
9.2 |
0.1 |
1% |
4.3.7 |
7.0 |
6.8 |
0.2 |
2% |
4.3.8 |
9.1 |
8.8 |
0.3 |
4% |
4.3.9 |
11.5 |
11.1 |
0.5 |
4% |
4.3.10 |
9.2 |
8.9 |
0.4 |
4% |
4.3.11 |
6.7 |
5.9 |
0.8 |
14% |
4.3.12 |
6.6 |
5.9 |
0.7 |
11% |
4.3.1 Does the agency have a process to estimate road user costs and use them to evaluate and select project strategies (full closure, night work, traffic management alternatives, detours, etc.) for type I and II projects? Thirty-seven agencies (74%) have a process to estimate road user costs. Several agencies cited use of software, such as QUEWZ, QuickZone, and other agency-developed applications, to analyze potential project strategies. One agency noted that they also incorporate past experience, engineering judgment, and historical knowledge in concert with software tools to make decisions on the appropriate strategies such as night work and detour routes around the project. Another agency cited consideration of road user costs in determining alternatives including detours, temporary roadway or shoulder construction, off-peak daytime work, night work, and the most appropriate project delivery or contracting method.
4.3.2 Does the agency develop a Transportation Management Plan that addresses all operational impacts focused on project congestion for type I and II projects? Thirty-four agencies (68%) develop a transportation management plan that addresses all operational impacts focused on project congestion for type I and II projects. Some agencies rated this question based on a formal TMP, while others rated it based on a plan very similar to the formal TMP and it’s elements (while not specifically called a TMP). Plans are initiated during the early planning states and updated and revised during the design and bid preparation phase. Strategies are also evaluated during construction and modified as needed.
4.3.3 Does the agency use multidisciplinary teams consisting of agency staff to develop Transportation Management Plans for type I and II projects? Thirty-six of the reporting agencies (72%) use multidisciplinary teams. These teams may consist of staff from planning, design, construction, operations, and other external stakeholders such as the public. In some cases, multidisciplinary teams are used primarily on high priority projects. One agency cited use of a formal multidisciplinary task force to minimize impacts from work zones. While the overall score for this question decreased compared to 2005, this was not a national trend and was primarily due to a small number of agencies. Most agencies reported no change in score. The scores for 9 agencies increased and 8 agency ratings decreased. With 3 agency ratings decreasing by a fair amount (3 or more points), the net change on this question was a decrease of 4%.
4.3.4 Does the agency perform constructability reviews that include project strategies to reduce congestion and traveler delays during construction and maintenance for type I and II projects? Out of the 50 responding States, 47 of them (94%) use constructability reviews on projects. Agencies may only require constructability reviews for complex projects, or may decide to use them on a project-by-project basis. One agency cited the recent establishment of a Constructability Reviews Unit for performing in-house reviews (small to medium sized projects) and administering outsourced reviews (larger projects) to minimize delay while maximizing productivity. One agency cited the use of reviews that focus solely on constructability without consideration of traffic impacts.
4.3.5. Does the agency use independent contractors or contractor associations to provide construction process input to expedite project contract time for type I and II projects? More than half of the agencies (62%) use contractor associations to provide construction process input. This practice is often executed primarily on complex projects. One agency cited use of contractor association representatives, concrete suppliers, and concrete products association representatives for input to help minimize impacts from lane closures. One agency cited use of this technique on major Design-Build projects. Workshop forums are also used to gain input from contractors.
4.3.6 Does the agency use scheduling techniques that are based on time and performance, such as the critical path method or parametric models, to determine contract performance times for type I and II projects? Forty-one agencies (82%) are using a technique to determine contract performance times for type I and II projects. Several agencies noted use of the critical path method during the construction phase to determine performance times. Some agencies use various project and program management tools to establish contract performance times.
4.3.7 Does the agency have a process to evaluate the appropriate use of ITS technologies to minimize congestion in and around work zones for type I, II, and III projects? Half of the agencies (50%) consider ITS technologies to minimize congestion in work zones. Agencies use stand-alone work zone ITS systems and also use existing, permanent ITS for monitoring and management. Some agencies may evaluate whether to implement ITS technologies on a project-by-project basis, while other agencies only consider ITS use for major projects. One agency noted that standard ITS elements are available on a checklist for consideration. One agency noted the need to deploy ITS in advance of the work zone to avoid providing information that is not timely enough to allow motorists to make appropriate route decisions. Several agencies stated that no formal evaluation process exists for ITS applications and that more guidance is needed in using this technology to mitigate work zone impacts. Some agencies noted that no formal evaluation process is used and that limited documentation is available on the effectiveness of ITS.
4.3.8 Does the agency use life-cycle costing when selecting materials to reduce the frequency and duration of work zones for type I, II, and III projects? To reduce the frequency and duration of work zones, life-cycle costing is used by 38 agencies (76%). One agency cited the use of results from life-cycle cost analysis to specify advanced mix designs, high strength concrete, and high strength steel. One agency noted that the process is used, but often the materials desired are cost prohibitive due to higher initial cost.
4.3.9 Does the agency have a process to assess projects for the use of positive separation devices for type I and II projects? Forty-seven agencies (94%) have a process to assess projects for the use of positive separation devices for type I and II projects. This was one of the highest scoring questions on the WZ SA. An agency may require the use of temporary concrete median barriers for major projects and on high speed facilities. Some agencies set standards and specify that certain project types require positive separation devices. One state noted that positive separation is required on some projects and optional on others.
4.3.10 Does the agency anticipate and design projects to mitigate future congestion impacts of repair and maintenance for type I, II, and III projects? Forty-two agencies (84%) incorporate features into their project designs that accommodate the need for future repair and/or maintenance activities. One agency cited the design of a wider inside shoulder for less traffic impact during maintenance operations. Full depth shoulders, tied shoulders, guardrail attachment points, and frontage roads were also cited by agencies as tools to mitigate future congestion during maintenance.
4.3.11 When developing the Traffic Control Plan for a project, does the agency involve contractors on type I and II projects? Contractors are involved with the development of traffic control plans in 27 agencies (54%). Often, contractors are used informally during constructability reviews or may be consulted during the design stage if needed. Additionally, agencies allow contractors to submit ideas for or revisions to the traffic control plan. The average rating for this question increased by 14% from 2005 to 2006. This does not appear to be a widespread national trend, but rather is due primarily to a subset of agencies with increased ratings (14 agencies), especially 5 agencies showing large increases in their ratings. For a few of these agencies, scores in the past had been zero so the increases indicated new attention to these activities.
4.3.12 When developing the Traffic Control Plan for a project, does the agency use computer modeling to assess Traffic Control Plan impacts on traffic flow characteristics such as speed, delay, and capacity for type I and II projects? Twenty six of the 50 responding agencies (52%) implement computer modeling in the development of traffic control plans. There was an 11% increase in average scores from the previous year on this question. This does not appear to be a widespread national trend, but rather is due primarily to a subset of agencies with increased ratings (12 agencies), especially 3 agencies that reported large score increases. One of these agencies noted the ongoing development of databases to support modeling. Some agencies use this computer modeling on a project-by-project basis (potentially for larger projects when higher impacts are anticipated) or on occasion to evaluate the potential impacts. Agencies reported using QuickZone, QUEWZ, and agency-developed spreadsheet tools for analyzing impacts. Simple capacity calculations are often used in conjunction with traffic volume data to estimate impacts for a project, network, or corridor.
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