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Section 2: Data Collection/Preliminary Design Preparation

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Overview

This section includes obtaining data necessary for making engineering and environmental decisions related to project design. Data collection efforts should be as complete as possible so project solutions providing the most benefit are selected.

This section includes the following tasks. The tasks are listed in approximate chronological order but may be performed concurrently in some areas.

20200. Conduct early coordination with stakeholders

20210. Prepare and execute additional agreements

20220. Review traffic data

20230. Obtain right of entry

20240. Obtain related data, plans, studies, and reports

20250. Obtain information on existing utilities

20260. Obtain traffic crash data

20270. Obtain hydraulic studies

20280. Obtain geospatial data

20290. Perform other surveys

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20200: Conduct early coordination with stakeholders

Description. Early coordination with resource and regulatory agencies and other stakeholders is vital in obtaining concerns and opportunities for a proposed project. Sometimes opportunities may be identified to perform joint activities with a project planned by an agency. Project managers can streamline the overall project development process by proactively seeking out potential stakeholders such as neighborhood associations, schools, fire and police departments, etc.

Permits from regulatory agencies may be required for construction activities affecting the respective resources. Resource agencies may require implementing mitigation measures where environmental effects cannot be avoided. Types of mitigation may include restoration or enhancement, creation, and preservation of natural resources. Mitigation can be a requirement in obtaining permits from regulatory agencies.

Pertinent Project Types. New construction, reconstruction and rehabilitation projects. Minor projects (2R, seal coat, overlay) may require coordination if a resource is known to exist within department right of way.

Responsible Party. Project manager

Subtasks.

Helpful Suggestions.

Authority.

Resource Material.

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20210: Prepare and execute additional agreements

Description. Existing agreements and contracts that TxDOT has with public entities, railroad companies, utility companies, and other agencies need to be identified and taken into consideration during project development. Identification of existing agreements also helps determine the possible need for additional agreements. Some agreements may need to be amended and the appropriate division can assist. The advance funding agreement should have been previously executed. See Task 10510: Prepare and execute advance funding agreements.

The following table lists the coordinating division of each type of additional agreement:

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Type of Agreement

Coordinating Division

Bridge projects between Texas and other states or between Texas and Mexico

Bridge

Drainage agreements

Right of Way or Maintenance

Joint-use agreements, see Task 40340: Prepare and execute joint-use, multiple-use agreements

Right of Way

Multiple-use agreements, see Task 40340: Prepare and execute joint-use, multiple-use agreements

Maintenance

Municipal maintenance

Maintenance

Natural Resource Conservation Service (NRCS)

Environmental Affairs

Railroad

Rail

Right of entry

Right of Way

Right of way (agreement to contribute funds)

Right of Way

U.S. Coast Guard (USCG)

Environmental Affairs

U.S. Army Corps of Engineers (USACE)

Environmental Affairs

U.S. Fish and Wildlife Service

Environmental Affairs

U.S. Geological Survey (USGS) - gaging stations

Bridge

Utility (pipelines, telephone, etc.)

Right of Way



Agreements or permits between TxDOT and other entities are required in the following situations:

Pertinent Project Types. All projects

Responsible Party. Project manager

Subtasks.

Critical Sequencing.

Authority Requirements.

Resource Material.

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20220: Review traffic data

Description. Traffic data is a key element in highway design. Traffic data requested earlier should be reviewed, and additional data should be obtained. See Task 10430: Obtain Traffic Data.

Pertinent Project Types. New construction, reconstruction, and rehabilitation projects

Responsible Party. Project manager

Resource Material.

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20230: Obtain right of entry

Description. Right of entry (ROE) is permission, granted by a landowner, for others to enter the landowner's property for a specific purpose. ROE should be obtained in writing on a form that is legally binding.

ROE requests to access railroad property should be processed through the district railroad coordinator or through the Traffic Operations Division - Rail Safety Section. Conditions may exist for entry on railroad property.

Consult with Design Division, Photogrammetry Section for their services which may not require entering private property. See Task 20280: Obtain geospatial data.

Pertinent Project Types. Projects requiring land surveying, environmental surveying, core drilling, rail construction and maintenance agreements, or other work activities outside public right of way.

Responsible Party. Survey, rail, and environmental personnel through the Project Manager

Subtasks.

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  • Identify properties requiring entry. This includes properties where work activities will be performed and properties that will be traveled upon to reach work activity sites.
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  • Research property ownership information - typically at county tax appraiser's office. District Right of Way personnel might be able to assist.
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  • If possible, meet the property owner to discuss the conditions for the ROE .
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  • Prepare letters to property owner(s) requesting permission to enter property. The letters may be sent by U.S. mail or courier delivery service.

Helpful Suggestions.

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  • Work with district survey coordinator, rail, and right of way personnel to develop appropriate wording for ROE letters. They may have a standard form letter.
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  • Keep the ROE permission request for engineering survey separate from environmental survey. Some property owners can become cautious about too much activity on their property.
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  • As a courtesy, send an extra copy of the ROE request letter for the landowner's records. Include a cover letter containing a description of the overall project and a description of the public involvement process, if applicable, and include a self-addressed, stamped envelope. This should reduce the number of follow-up inquiries and efficiently direct inquiries received.
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  • Be prompt and mindful of time allowed by the ROE. Remember to leave landowner’s premises as they were found and relock gates.

If consultants are performing survey work and obtaining ROE, assist with the following:

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  • The project manager should supply the consultant with copies of a TxDOT cover letter for attachment to the consultant's ROE request letter. This can assist the consultant in securing ROE.
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  • The consultant should forward copies of ROE request letters signed by landowners to the TxDOT project manager. These letters should be kept with project records.

Critical Sequencing.

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  • This task must be done before entering private property.
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  • Because it might take months to obtain permission from property owners living out of town or out of state, begin this task soon after identifying its need.
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  • For time‑sensitive ROE requests, landowners may send a signed PDF letter by email or FAX.

Resource Material.

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20240: Obtain related data, plans, studies and reports

Description. Studies and reports can provide information that will assist in decision making and help avoid “re-inventing the wheel.”

Consider the following sources:

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  • Project history files
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  • Previously studied but suspended projects
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  • Formal or informal studies addressing a specific issue
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  • Relevant project information for adjoining or parallel routes
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  • Studies conducted by other agencies or special districts (e.g. MPO, flood control district) related to the proposed project concept or having possible impact on project design.

Pertinent Project Types. All projects

Responsible Party. Project manager

Subtasks.

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  • Identify and contact individuals having knowledge of relevant information.
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  • Research names of property owners along the project for use in future public involvement.
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  • Maintain an inventory of information received.

Helpful Suggestions.

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  • Identifying and locating information may depend on memories of individuals who worked on related projects.
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  • When requesting information, be as specific as possible about information being sought.
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  • Information may be obtained through informal interviews.
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  • Search for related research at the Center for Transportation Research Library catalog, CTR.
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  • City and county offices have information on local circulation plans or planned residential or commercial development.
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  • In urban areas, it may be helpful to contact the local transit operator for information.
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  • Private companies may have reports or studies (e.g., a traffic study developed for a commercial property owner).

Related information typically available within TxDOT includes the following sources:

Critical Sequencing.

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  • Perform data collection as soon as work is authorized to begin on preliminary design.
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20250: Obtain information on existing utilities

Description. Utility locations must be identified early in project development. Coordination with utility owners is required when existing utilities are present.

Pertinent Project Types. All projects except preventive maintenance and restoration projects

Responsible Party. Project manager

Subtasks.

Helpful Suggestions.

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  • If the project is proposed on new location, review recent area wide aerial photography for evidence of underground transmission lines. Contact Design Division Photogrammetry Section for possible assistance.
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  • Establish the locations of existing right of way near utilities. See Task 40100: Perform preliminary right of way research.
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  • Consider using subsurface utility engineering (SUE). See Task 40110: Locate existing utilities.
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  • Utility owner representatives may need reminders about information requests; mark your calendar for follow-up contacts. Expect four to six weeks for a response.
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  • Citizens ultimately pay for utility relocations, so avoid or minimize relocations when possible.
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  • Surveys should be used to locate above-ground utilities and signs for underground utilities.

Critical Sequencing.

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  • Identify utility locations early so there is time to design around them or determine utility adjustment costs.

Resource Material.

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20260: Obtain traffic crash data

Description. A crash analysis is essential in the design process for a project involving an existing transportation facility. The Traffic Operations Division is responsible for collecting State crash reports.

Traffic crashes, which result in injury to, or death of, a person, or that result in damage to the property of any one person to the apparent extent of $1,000 or more are required to be reported to the department, in writing, within 10 days. The vehicle operator shall submit a written report, if there was no investigating law enforcement officer. In the case of a crash investigating law enforcement officer, the officer shall provide the written report within the same 10 day time requirement. See Transportation Code Chapter 550 - Accidents and Accident Reports.

Pertinent Project Types. All projects except preventive maintenance.

Responsible Party. Project manager

Subtasks.

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  • If possible, obtain crash data for at least a three-year period.
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  • Obtain information about pertinent, physical features of the facility such as geometrics and traffic (i.e., average annual daily traffic).
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  • Observe traffic movements at the location during pertinent times (e.g., rush hour).
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  • Analyze the data. Identify factors contributing to crashes, look for similarities, patterns, or abrupt changes over time in the way crashes are happening.
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  • Consider design features that might reduce potential for crashes, reduce crash severity, or improve operations.

Helpful Suggestions.

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  • Through the district traffic operations section, contact Traffic Operation Division (TRF) to obtain access and training for the Crash Records Information System (CRIS).
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  • The Traffic Operations Division (TRF) can also assist in research, analyzing, and evaluating crash data.
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  • The district maintenance supervisor is a good source for traffic crash information.
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  • Local authorities may also assist in identifying or tracking problems as they develop.
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  • AASHTO Highway Safety Manual analysis can provide quantitative analysis and countermeasures to address safety.
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  • AASHTO Safety Analyst software can proactively predict safety improvements and optimize crash reduction as opposed to costly waiting for crashes to warrant an action.
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  • When data alone is insufficient, copies of a law enforcement officer’s report may be obtained from CRIS.

Resource Material.

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20270: Obtain hydraulic studies

Description. To determine preliminary drainage structure requirements (i.e.,“floodplain screening”), obtain and review existing studies. Floodplain studies and other hydraulic data may be prepared by or for the Federal Emergency Management Agency (FEMA), drainage districts, river authorities, cities, and counties.

Numerous communities throughout Texas participate in the National Flood Insurance Program (NFIP). FEMA requires an appointed State Coordinating Agency for the NFIP communities, which is the Texas Water Development Board (TWDB). For streams within jurisdiction of a participating community, FEMA rules and regulations apply.

In instances where TxDOT facilities are located within bounds of a Flood Insurance Study (FIS), TxDOT needs to investigate effects that proposed construction will have on the published Flood Insurance Study. The studies have been compiled by organizations such as the U.S. Army Corps of Engineers (USACE), the U.S. Geological Survey (USGS), the U.S. Natural Resources Conservation Service (NRCS), various local governmental entities, and private consultants.

To analyze existing hydraulics, obtain the FEMA study, or other relevant floodplain study; see the Hydraulic Design Manual. Use this information to analyze the existing location and develop design alternatives that follow FEMA guidelines, when applicable.

Pertinent Project Types. Projects that might change the water surface elevation in a FEMA controlled floodplain. Some examples of these projects are as follows:

Responsible Party. Project manager

Subtasks.

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  • Comply with minimum FEMA rules and regulations. Determine whether the project has the potential to affect a stream within jurisdiction of a city or community participating in the National Flood Insurance Program.
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  • Contact the Design Division Hydraulics Branch to obtain the relevant hydraulic study (i.e., computer model).
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  • Perform modeling and coordination as discussed in the TxDOT Hydraulic Design Manual. Ask for assistance from the DES Hydraulics Branch as needed.

Helpful Suggestions.

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  • The backwater profile program used in originally developing a study may have been one of several types and from one of several sources. In Texas, the model most commonly used is the HEC-2 Water Surface Profile model from the U.S. Army Corps of Engineers. Typically, FEMA encourages that the model be updated to the most current acceptable model. If the stream was originally modeled using HEC-2, subsequent models should be done using HEC-RAS.
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  • Floodway and floodplain encroachments must be explained in the environmental document.
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  • Obtaining FEMA studies can take several months.

Resource Material.

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20280: Obtain geospatial data

Description. Geospatial data includes digital maps, terrain models, and orthophotography. The data may already exist (e.g., Google Maps) or, depending on project requirements, may need to be created. Geospatial data can be created using various technologies.

Small areas, less than 10 acres:

A land surveying task is accomplished using either optical surveying equipment (e.g. a total station) or by GPS. Individual points on the ground are located by the surveyor. In the office, the surveyed point data is processed creating a planimetric map and digital terrain model (DTM).

The procedures in Static LiDAR surveying are similar to land surveying in that a surveying instrument is setup on a tripod at the project site. Rather than locate individual points on the ground, the LiDAR scanner collects thousands to millions of individual points creating a dense “cloud” of located points. In the office, data is extracted from the “point cloud” using specialized software.

The following are more cost-effective for areas greater than 10 acres:

Aerial photogrammetry typically uses piloted aircraft equipped with a large-format metric mapping camera; however, UAS (unmanned aerial systems) and small format cameras can also be used.

Airborne LiDAR uses one or more scanners mounted on an aircraft. The aircraft can be rotary-wing, like a helicopter, or fixed-wing. The mapping data is extracted from the point cloud.

Close-range photogrammetry can be static with the camera held in a fixed position, mobile, or airborne. Three dimensional data is extracted from the imagery to produce planimetric maps and DTM data.

Mobile LiDAR uses one or more scanners mounted on a moving vehicle in contact with the earth’s surface. The vehicle can be a car or truck operating on a roadway, a vehicle operating on a rail line, or even a boat. Mobile LiDAR systems produce dense point clouds from which data can be extracted.

Planimetric mapping and DTM extraction are done using stereoscopic viewing equipment and specialized software.

Most mapping is done using a network of ground control points. These are points that have been precisely located on the ground using surveying equipment. The control points form a geospatial reference frame for the subsequent mapping task. Often the ground control points are “targeted” using a painted “X” or similar figure. The target allows easy identification of the ground control point in the point cloud or on the photograph. Targeting is typically done prior to data collection.

Aerial photography can be collected, but not controlled. In this case, the imagery is primarily used to give an overview of a proposed corridor project or other large study area. The imagery can roughly be georegistered, but should not be used for precise mapping.

Pertinent Project Types. All Projects

Responsible Party. Project manager

Subtasks.

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  • Determine if existing data exists. If it does, determine suitability for use.
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  • Discuss data needs with the area engineer, district land surveyor, or geospatial data subject matter experts in the Design Division - Photogrammetry Section (DES-PS).
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  • Determine the technology to be used based on data needs assessment. Note that DES-PS provides complete in-house photogrammetric services. LiDAR services are currently contracted to outside firms.
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  • If a photogrammetric solution is selected, contact DES-PS for flight and control planning. The section will provide a ground control plan showing the location of targets to be placed on the ground. The targets will be placed and surveyed using either in-house survey staff or by outside contractors. DES-PS will schedule the aerial flight mission once the targets are in place.
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  • If a LiDAR solution is selected, consult with DES-PS.

Additional subtasks for controlled aerial photography.

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  • Conduct or contract out field surveys to obtain ground control coordinates and to lay out ground panels. A registered professional land surveyor (RPLS) should perform the surveying work.
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  • Provide ground control coordinates to DES-PS.

Helpful Suggestions.

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  • Knowing which technology or combination of technologies to use can be a complicated matter. In general, project size determines which technology will be most effective. Contact DES-PS.
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  • Plan for a long lead-time before the finished product becomes available.
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  • Check with the DES-PS for scheduling.
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  • Digital orthophotography is available through the DES-PS. Lower resolution digital ortho is available from the Texas Natural Resource Information System (TNRIS) at www.tnris.org. TNRIS also has some LiDAR data available.
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  • When identifying the photography coverage area, consider including intersecting side roads, stream crossings, or complex drainage areas.
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  • Producing mapping in urban areas requires more effort than in rural areas due to the complexity of the urban areas.
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  • Be sure to follow up on delivering survey control data to DES-PS because lack of the control data can delay production of DTMs or planimetrics.
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  • For projects passing through areas of heavy vegetation, control surveying and the photography flight should occur during winter months when foliage is minimal.
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  • For large projects, consider performing control surveying in phases so panels can be more easily set up and maintained.
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20290: Perform other surveys

Description. Given the type and extent of existing data available for a project, additional data is sometimes needed to support decisions during preliminary design. A survey is a data collection effort. It is the type of data, level of detail, and collection process that defines a survey. The survey could involve reconnaissance trips to the project site or a review of maps and plans. Level of detail could range from a general listing of items to controlled surveys tying features to a coordinate system. New ways of combining data will improve capability to coordinate activities.

As a large or complex project develops, it is common to determine that existing data is insufficient or needs updating. See Task 20505: Perform preliminary geotechnical surveys and Task 20280: Obtain geospatial data. In addition to preliminary geotechnical surveys and topographic surveys, other surveys may include the following:

Pertinent Project Types. All projects

Responsible Party. Project manager

Subtasks.

Helpful Suggestions.

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  • Data collection is time consuming, so get only as much detail as necessary.
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