Anchor: #i1017713

Section 2: Data Collection/Preliminary Design Preparation

Anchor: #i1017718


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.

2110. Conduct early coordination with stakeholders

2120. Prepare and execute additional agreements

2140. Review traffic data

2150. Obtain right of entry

2160. Obtain related data, plans, studies and reports

1010. Perform site visit

2180. Obtain information on existing utilities

2190. Obtain traffic crash data

2200. Obtain hydraulic studies

2220. Obtain aerial photography/planimetrics/DTMs/digital orthophotography

2230. Perform topographic surveys

2240. Perform other surveys

Anchor: #i1017740

2110: 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/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 State right of way.

Responsible Party. Project manager


  • Coordinate with district environmental coordinator and roadway design engineer.
  • Identify resource and regulatory agencies and stakeholders.
  • Identify environmental/design constraints.
  • Identify possible construction methods.
  • Explore project design modifications to avoid, minimize, and/or mitigate effects to natural resources.

Helpful Suggestions.

  • Refer to information on Interagency Coordination/Permits. (See Chapter 3, Section 2 Interagency Coordination/Permits).
  • Early coordination during project planning and development is essential in advancing a project to construction on schedule. Coordination continues throughout the process including construction and maintenance, based on the project's environmental commitments.

Authority Requirements. National Environmental Policy Act (NEPA) 1969

Resource Material. TxDOT Environmental Manual

Anchor: #i1017868

2120: 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 (see 1610: Prepare and execute advance funding agreements) should have been previously executed.

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

Anchor: #i1011478Additional Agreements

Type of Agreement

Coordinating Division

Agreements with other states

Contract Services Office

Drainage agreements

Right of Way and Design

Joint-use agreements (see 4425: Prepare and execute joint-use, multiple-use agreements)

Right of Way

Multiple-use agreements (see 4425: Prepare and execute joint-use, multiple-use agreements)


Municipal maintenance


National Resource Conservation Service (formerly, U.S. Soil Conservation Service)

Environmental Affairs

Railroad (see 2330: Initiate railroad coordination)

Railroad Section of Traffic Operations

Right of entry

Right of Way

Right of way (agreement to contribute funds)

Right of Way

U.S. Coast Guard

Environmental Affairs

U.S. Corps of Engineers

Environmental Affairs

U.S. Department of Interior Water and Power Resources Service

Environmental Affairs

U.S. Geological Survey (for gaging stations)

Design - Bridge Planning

Utility (pipelines, telephone, etc.)

Right of Way

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

  • work is performed within jurisdiction of another entity (e.g., railroads)
  • other entities construct facilities (e.g., driveways, utilities) on State right of way
  • funds are provided by another entity
  • other entities agree to maintain the facility.

Pertinent Project Types. All projects.

Responsible Party. Project manager


  • Identify existing agreements.
  • Determine need for additional agreements and amendments to existing agreements.
  • Coordinate with district/division staff to develop and execute agreements.

Critical Sequencing. Develop agreements as early as possible to allow approval time.

Authority Requirements.

Resource Material.

Anchor: #i1018058

2140: Review traffic data

Description. Traffic data is a key element in highway design. Traffic data requested earlier (see 1430: Obtain Traffic Data) should be reviewed, and additional data should be obtained.

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

Responsible Party. Project manager

Resource Material.

Anchor: #i1018118

2150: 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 Railroad Section of the Traffic Operations Division.

Examples of ROE permission request letters for land surveys ( LANDSURV) and environmental surveys ( ENVIRSUR) along with an example cover letter ( COVERLET) are available.

Pertinent Project Types. Projects requiring land surveying, environmental surveying, core drilling, or other work activities (not construction) outside public right of way.

Responsible Party. Project manager


  • 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.
  • Research property ownership information - typically at county tax appraiser's office. District Right of Way staff might be able to assist.
  • Prepare letters to property owners requesting permission to enter properties. The letters may be sent by U.S. mail.

Helpful Suggestions.

  • Work with district right of way staff to develop appropriate wording for permission letters. They will probably have a standard form letter.
  • Consider keeping the ROE permission request for engineering surveys separate from environmental surveys. Some property owners can become cautious about too much activity on their property. A ROE permission request letter for land surveys ( LANDSURV) and environmental surveys ( ENVIRSUR) are available.
  • 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. An example ROE cover letter ( COVERLET) is available.
  • If consultants are performing survey work and obtaining ROE
    • 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.
    • 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.
  • For time-sensitive ROE requests, landowners may send their signed letters by FAX as a last resort.

Critical Sequencing.

  • This task must be done before entering private property.
  • Because it might take months to obtain permission from property owners, begin this task soon after identifying its need.

Resource Material. TxDOT Right of Way Collection

Anchor: #i1018287

2160: 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:

  • project history files
  • previously studied but suspended projects
  • formal or informal studies addressing a specific issue
  • relevant project information for adjoining or parallel routes
  • studies conducted by other agencies or special districts (e.g. 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


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

Helpful Suggestions.

  • Identifying and locating information often depends on memories of individuals who worked on related projects.
  • When requesting information, be as specific as possible about information being sought.
  • Information may be obtained through informal interviews.
  • Search for related research finding in the TxDOT Research Library, available on TxDOT's Research and Technology Implementation Office (RTI) internet site.
  • City and county offices have information on local circulation plans or planned residential or commercial development.
  • In urban areas, it may be helpful to contact the local transit operator for information.
  • 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:
    • “as-built” construction plans
    • right of way maps
    • bridge inventory data
    • traffic signal studies
    • bicycle plans
    • environmental studies and schematics for previous or adjacent projects
    • Automated Road Inventory Diagrams (ARI) for all on-system highways - available through the Transportation Planning and Programming Division
    • traffic data (see 1430: Obtain Traffic Data.)
    • traffic accident data (see 2190: Obtain Traffic Crash Data.)
    • archived project history files
    • Pavement Management System (PMS) data
    • existing hydrologic/hydraulic reports
    • existing geotechnical reports
    • local agency comprehensive plans.

Critical Sequencing. Perform data collection as soon as work is authorized to begin on preliminary design.

Anchor: #i1018546

2180: 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


  • Coordinate with district utility coordinator as needed.
  • Review “as-built” construction plans and permit records to identify existing utility owners.
  • Observe utility locator markers and signs in the field and note owner's name.
  • Contact municipalities adjacent to the project and request help in identifying utility owners to contact.
  • Provide utility owners with the project “footprint” and request information on their utility locations.
  • Conduct utility field surveys. (See 4200: Locate existing utilities).

Helpful Suggestions.

  • If the project is proposed on new location, review recent area wide aerial photography for evidence of underground transmission lines.
  • 4000: Perform preliminary right of way research to establish the locations of existing right of way near utilities
  • Consider using subsurface utility engineering. (See 4200: Locate existing utilities).
  • Utility owner representatives may need reminders about information requests; mark your calendar for follow-up contacts. Expect four to six weeks for a response.
  • Citizens ultimately pay for utility relocations, so avoid or minimize relocations when possible.
  • Topographic surveys (see 2230: Perform topographic surveys) should be used to locate above ground utilities and signs for underground utilities.

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

Resource Material. TxDOT ROW Utility Manual

Anchor: #i1018678

2190: Obtain traffic crash data

Description. A crash analysis is essential in the design process for a project involving an existing transportation facility.

Traffic crashes (on- and off-system) investigated by law enforcement officials, 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 Texas Department of Transportation (TxDOT).

Pertinent Project Types. All projects except preventive maintenance.

Responsible Party. Project manager


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

Helpful Suggestions.

  • Crash records are accessible to TxDOT and DPS personnel who have been given access to the Crash Records Information System (CRIS). Every district has at least one employee who has access. That employee is usually in the District’s Traffic Operations Section.
  • The Traffic Operations division (TRF) can also assist in obtaining and analyzing crash data.
  • The maintenance supervisor is a good source for traffic crash information.
  • Local authorities may also assist in identifying or tracking problems as they develop.
  • When data alone is insufficient, copies of a law enforcement officer’s report may be obtained from CRIS.

Resource Material.

Anchor: #i1018833

2200: 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. 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, 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 Corps of Engineers, the U.S. Geological Survey, the U.S. Natural Resources Conservation Service (formerly the Soil Conservation Service), various local governmental entities, and private consultants.

To analyze existing hydraulics, obtain the FEMA study (see the Hydraulic Design Manual) or other relevant floodplain study. 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:

  • a new structure (new profile) over a stream
  • project generates an increase in impermeable cover in a watershed (not ultimate development)
  • riprap added to a stream bank or bed
  • addition of concrete median barrier to an existing facility.

Responsible Party. Project manager


  • 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. If so, compliance with minimum FEMA rules and regulations is required.
  • If FEMA compliance is required, contact the Hydraulics Branch of the Roadway Design Section in the Design Division to obtain the relevant hydraulic study (i.e., computer model). Perform modeling and coordination as discussed in the TxDOT Hydraulic Design Manual section on the Federal Emergency Management Agency. Ask for assistance from the Hydraulics Branch as needed.

Helpful Suggestions.

  • 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 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.
  • Floodway and floodplain encroachments must be explained in the environmental document.
  • Detailed FEMA requirements are discussed in the TxDOT Hydraulic Design Manual
  • Obtaining FEMA studies can take several months.

Resource Material.

Anchor: #i1018936

2220: Obtain aerial photography/ planimetrics/ DTMs/ digital orthophotography

Description. Controlled aerial photography is tied to surveyed panels that are visible in the aerial photos. Controlled aerial photography is used to obtain the following:

Uncontrolled aerial photography involves no ties to ground controls. Uncontrolled aerial photography can be used to produce photo mosaics. Mosaics are used to locate potential project corridors or for displays at public meetings and hearings.

Pertinent Project Types.

  • Projects where obtaining data from controlled aerial photography is more feasible than obtaining data solely from field surveying.
  • Projects involving a transportation corridor or other large study area may require uncontrolled aerial photography.

Responsible Party. Project manager


  • Determine whether aerial photography already exists and is current enough to be useful.
  • Discuss aerial photography needs with the area engineer, district land surveyor, or the Photogrammetry Branch of the Technology Services Division (TSD); aerial photography may be done through consultant contracts or the Photogrammetry Branch of TSD.
  • Complete the TSD Photogrammetric Services Request Form and provide a flight map showing the area where photography is needed in coordination with the district land surveyor or area engineer. Contact TSD for flight map requirements.

Additional sub-tasks for controlled aerial photography

  • 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.
  • Follow up on providing ground control coordinates to TSD.

Helpful Suggestions.

  • Plan for a long lead-time before the finished product becomes available.
  • Check with the Photogrammetry Branch of TSD for scheduling.
  • Digital orthophotography is available through the Photogrammetry Branch of TSD. Lower resolution digital ortho is available from the Texas Natural Resource Information System (TNRIS) at
  • In determining the photography coverage area, consider including intersecting side roads, stream crossings, or complex drainage areas. Try to avoid requesting additional flights for minor areas such as these.
  • Producing planimetric mapping in urban areas requires more effort than in rural areas due to the amount of topographic features.
  • Be sure to follow up on delivering survey control data to TSD because lack of the control data can delay production of DTMs or planimetrics.
  • For projects passing through areas of heavy vegetation, control surveying and the photography flight should occur during winter months when foliage is minimal.
  • For large projects, consider performing control surveying in phases so panels can be more easily set up and maintained. Maintaining and protecting many, widespread panels from natural elements and animals in remote areas can be challenging (i.e., panels may become tasty morsels for cows and goats). A length of ten miles is suggested for maintaining panels for an aerial flight. Longer projects can be done in phases. Phasing requires close coordination with the aerial photography crew.
  • Additional survey work may be needed such as for establishing or re-establishing permanent, survey control monuments.
Anchor: #i1019079

2230: Perform topographic surveys

Description. A topographic survey is performed at this stage as a preliminary field survey to locate pertinent, existing features along a project. Data from a topographic survey may be used to create or supplement a digital terrain model (DTM) or planimetric map.

The need for a full topographic survey versus aerial photography should be analyzed. There may be cases (e.g., small project sites) where it is more feasible to perform a topographic survey rather than obtain aerial photography. When aerial photography is the main source of data, a minor topographic survey may still be needed if areas were “obscured” (i.e., covered by trees) in the photography or if more detailed survey data is needed (e.g., culvert sizes/elevations and bridge clearances).

Pertinent Project Types. All projects except preventive maintenance projects.

Responsible Party. Project manager


  • Obtain the right of entry, if applicable. A right of entry (see 2150: Obtain right of entry) or other written evidence of permission must always be obtained before entering private property.
  • Locate pertinent objects and above-ground features, typically including
    • drainage structures (such as culverts, ditches, inlets, manholes, and outfalls)
    • streams (obtain cross sections at locations directed by the drainage engineer)
    • bridges (note horizontal and vertical clearances, abutment and bent locations, deck and bearing seat elevations, and railing type)
    • utilities (signs or markers showing the presence of underground utilities, valves, manholes, pumps, backflow preventers, vents, meters, poles, and guy wires. If utility marking is requested, locate all paint markings and identify owner/contact numbers).
    • large and significant trees (identify species and trunk diameter)
    • fences (type of fence is important) and gates
    • sidewalks (identify if concrete, asphalt, or other)
    • driveways (identify if concrete, asphalt, or gravel)
    • signs (roadway and private) - include type of sign and labels/marking on signs
    • right of way documentation (If right of way survey is not performed.)
  • Process surveying data to create a plan view of existing features and original cross-section and DTM information.

Helpful Suggestions. Plan the survey for all design, environmental, aesthetic and landscape needs to minimize the number of survey trips. If applicable, provide limits of requested survey area and provide ortho photos of appropriate area to help define request.

Anchor: #i1019185

2240: 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.

As a large or complex project develops, it is common to determine that existing data is insufficient or needs updating. In addition to topographic surveys (see 2230: Perform topographic surveys) and preliminary geotechnical surveys (see 2505: Perform preliminary geotechnical surveys), other surveys may include the following:

  • ROW/property surveys (see 4000: Perform preliminary right of way research)
  • utility surveys (see 4200:Locate existing utilities) to collect information on location and type of existing utilities
  • survey of historical buildings, cemeteries, and other cultural resources
  • survey of turning movements and through traffic at an intersection
  • origin/destination traffic survey
  • traffic generator survey and classification counts
  • vehicle classification survey to determine the percentage of truck traffic
  • environmental survey to determine the type and location of environmental features.

Pertinent Project Types. All projects

Responsible Party. Project manager


  • Identify data needs.
  • Define the survey in terms of needed type and limits of information, level of detail, process of collection, and data format.
  • Coordinate with appropriate staff to schedule the survey.
  • Depending on survey type, it may be necessary to obtain right of entry (see 2150: obtain right of entry). A right of entry or other written evidence of permission must always be obtained before entering private property.
  • Information on subsurface utility engineering (SUE) is available under Task 4200: Locate existing utilities.

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

Previous page  Next page   Title page