Highway Design - Transportation.ky.gov

SURVEYINGHD-302Survey ControlHD-302.4.2Horizontal Project ControlSet monuments as required by project conditions, generally no more than 2640feet apart and preferably intervisible with at least two other monuments.Minimum spacing for monuments is 1000 feet when using GNSS methods or 500feet when using conventional survey methods.If conventional methods must be used, horizontal surveys may be specified asSecond Order Class I or Second Order Class II depending on the precision required(such as, bridge or tunnel control).HD-302.4.3Vertical Project ControlSet monuments as required by project conditions, generally no more than 1500feet apart. When feasible, utilize horizontal project control monuments as verticalcontrol monuments.The 1 centimeter equivalent for conventional vertical surveys is Second OrderClass I. See Exhibit 300-03 for more information.HD-302.5SUPPLEMENTAL CONTROLSupplemental control should have a 2 centimeter network accuracy, 95 percentconfidence, and be tied to project control monuments. Supplemental controlpoints may be used for establishing photogrammetric control, Light Detection andRanging (LiDAR) control, and right-of-way survey control unless specifiedotherwise.HD-302.5.1Supplemental Control MonumentationSupplemental control monumentation may be pipe or rebar (18 inches in length),PK nails in pavement, chiseled crosses in concrete, or similar material. Plastic capsshould be used for horizontal control and metal caps should be used for verticalcontrol. “KYTC” shall be legible on all caps.HD-302.5.2Aerial Mapping ControlAll control set for KYTC Aerial Mapping shall be tied to primary control and spacedas required by project conditions. Project control may be used if no primarycontrol is available.HD-302.5.2.1 Photogrammetric Panel PointsControl points utilized in photogrammetry are commonly referred to as “panelpoints” and are designated by an “x,” “v,” or open center cross with approximately5 feet legs. The legs of the cross are made of cloth, plastic, or paint. The panels areusually white in order to contrast with the ground; however, on concretepavements and extremely colored barren soils, it is best to use dark gray or blackmaterials. Control points should be paneled in advance of flying to ensure visibilityin the acquired photography.03/17Page 3 of 5

SURVEYINGSurvey ControlHD-302HD-302.5.2.2 LiDAR Ground Control Points (GCP)Aerial LiDAR differs from photogrammetry in that features are not visible in LiDARdatasets as in photography. (For example, a manhole would not be a discerniblefeature in an aerial LiDAR dataset.) For that reason, control placed for Aerial LiDARprojects do not need to be paneled and can be placed after the LiDAR acquisitionis complete, assuming ground conditions have not changed between LiDARacquisition and control survey. GCP preference should be given to pointsassociated to permanent, recoverable structures which may be used in futuresurvey work. Examples include manholes, curbs, utility structures, etc.HD-302.5.3Mobile Terrestrial Laser Scanning (MTLS) ControlGlobal Navigation Satellite System (GNSS) control stations used to control thepost-processed kinematic adjustment of the MTLS data shall be placed at amaximum of 5-mile intervals. In no case should the processed baseline exceed 5miles in length. Short baselines contribute to the best possible positional accuracyoutcome. Dual redundant GNSS base stations are highly recommended to guardagainst the possibility of wasted effort and useless data from base station failuredue to equipment, accident, or human error in station setup. Dual base stationsalso allow redundant post-processing and 10-mile baseline post-processing in caseof a base station failure.Locate one base station near the beginning of the project and another near theend of the project. The horizontal accuracy standard of control stations shall besecond order or better, and the vertical accuracy standard shall be third order orbetter as defined for project and supplemental control.Mobile Mapping control falls under the categories of “Transformation” or“Validation” control points. Transformation points serve as control for processingof the point clouds. Validation points are used to check the geospatial dataadjustment to the transformation points and allow for Quality Assurance/QualityControl (QA/QC) checks of the adjusted scan data. Both types of points should beplaced throughout at even intervals. Transformation points should be placedbefore and after expected obstructions, such as bridges.For MTLS surveys, the scanned area shall have control on both sides of theroadway with transformation points at a maximum of 1500-foot roadwaycenterline stationing intervals and validation points at a maximum of 500-footroadway centerline stationing intervals. MTLS surveys require local points to havesurveyed local positional accuracies of Hz 15mm and Z 15mm or better.Differential digital leveling is the preferred method of establishing transformationand validation point elevations.03/17Page 4 of 5

SURVEYINGHD-302Survey ControlHD-302.5.4Stationary Terrestrial Laser Scan (STLS) ControlTotal station targets reduce pointing error when placed at long distances. Laserscanning targets, however, are designed for a specific distance. Most laserscanners do not have telescopes to orient the instrument to a backsight. Vendorspecific targets tuned for the laser scanner frequency are recommended.Best results are typically seen when the targeted control stations are evenlyspaced horizontally throughout the scan. Variation in target elevations isdesirable. Targets should be placed at the recommended optimal distance fromthe scanner and scanned at high-density as recommended by the STLSmanufacturer.Hard surface topographic STLS surveys require control and validation pointsurveyed local positional accuracies of Hz 15mm and Z 15mm.HD-302.6DELIVERABLESFiles shall have non-proprietary format point data showing applied corrections. Allpoint, elevation, and metadata data used to calibrate, process, and validatecontrol points shall be submitted on portable media. A Surveyor’s Report isrequired (HD-301.6).HD-302.7QUALITY ASSURANCE/QUALITY CONTROL (QA/QC)Quality of the control data is essential to the quality of the entire survey and, byextension, the entire project. Minimally, the following items should be verifiedand submitted: Correct coordinate systemCorrect elevation datumProject Datum Factor, if usedUnedited raw filesRotationTranslationCorrection FactorsShown ties to existing Primary ControlLabeled types of monumentsNOTE: Due to the evolving software and mapping techniques for LiDAR technology, theprocedures listed in the previous pages may be altered with approval from the KYTC State SurveyCoordinator. 03/17Page 5 of 5

HD-303ChapterSURVEYINGSubjectData CollectionHD-303.1OVERVIEWThe degree of precision of all surveys is determined by the final intended use ofthe data. Generally, when new surveys are being undertaken, a preliminarysurvey should be to the same order as that required for the final survey. In somesituations, a preliminary survey for mapping or reconnaissance studies may be toa lesser order with approval of the KYTC State Survey Coordinator.HD-303.2SURVEY FIELD CREW RESPONSIBILITIESFor all KYTC projects, survey field crews are responsible for processing their dataand delivering a design (.dgn) file, digital terrain model (.dtm) file, and geometry(.alg) file. KYTC field crews are responsible for final checking and the assurance ofthe accuracy of all survey products delivered to the design office. Consultants mayfollow their internal Quality Assurance/Quality Control (QA/QC) procedures.HD-303.3SAFETYSurveyors work in hazardous environments, such as rugged terrain or in thevicinity of high-speed traffic and construction equipment. Working in theseconditions requires a constant awareness of the need for safety.When working in or near traffic, survey crew signing must be in place beforesurvey work begins. Survey signing should comply with the recommendations inthe most recent Manual on Uniform Traffic Control Devices (MUTCD) and will becoordinated with the district. Survey conditions should be suspended whenuncontrollable hazards develop, and work may be resumed only when safeworking conditions have been restored. Personnel must be particularly aware ofavoiding the creation of hazards when working on private property.HD-303.4ELECTRONIC DATA COLLECTORSThe electronic data collectors (electronic field books) selected for use shall notallow the data to be deleted until it has been sent to a printer or a computer. Ifan error is made in the field, the data collector retains both the error and thecorrection.03/17Page 1 of 3

SURVEYINGHD-303Data CollectionHD-303.4ELECTRONIC DATA COLLECTORS (cont.)As standard procedure to ensure that a permanent record of the original fieldworkis available, any agent of KYTC using electronic data collectors should comply withthe following practices: Download the original data into a computer and copy (unedited) to apermanent medium. Produce a hard-copy printout of the data before any editing takes place. Do any editing or subsequent changes to the data on copies of the originaldata. Never alter the original data. In any subsequent submittals of project information, treat the permanentmedium and the hardcopy printout, cited before, as a traditional field book. Electronic data files should be submitted in the approved KYTC format. Ifsubmitted in a text file, the following format shall be used: point number,Northing, Easting, elevation, feature code.Note: All survey and Digital Terrain Model (DTM) information for KYTC projectsshall utilize the KYTC feature codes list. The current feature codes list can be foundon the KYTC Highway Design website under Survey AL TERRAIN MODEL (DTM)A DTM is a three-dimensional representation of the surface of the earth. Theaccuracy of the DTM should reflect its intended use.Cross-sections and profiles needed for plan development and documentation shallbe derived from the DTMs.DTMs are created from breaklines and random points. Breaklines are linearfeatures that locate “breaks” (changes) in the earth’s surface, such as changes inslope. Examples of breaklines are the crown of pavement, edge of pavement,edge of shoulder, flow line, top of curb, bottom of slope, top of slope, bottom ofditch, and top of ridge.Random points are used to define the surface between breaklines. These pointsare spot elevations at various or key locations. Random points are generallycollected in a grid with a nominal spacing of 25 to 50 feet. Additional points maybe added to define high and low spots in terrains as needed. This spacing can varywidely depending on the regularity of the surface being surveyed.The surveyor shall be responsible for adequate breaklines and random points toensure that the DTM accurately reflects the surface. Additional care shall be takenin the collection of breaklines in areas around bridges and other structures,streams, and other sensitive locations.03/17Page 2 of 3

SURVEYINGHD-303Data CollectionHD-303.5DIGITAL TERRAIN MODEL (DTM) (cont.)At bridge abutments, wing walls, ends of pipes and culverts, curbs, retaining walls,and any other vertical-type situation, breaklines at both the top and bottom of thefeature are necessary for the definition of the surface.Take breakline data in a directional sequence. Do not jump back and forth on thesame breakline. The rodman should be knowledgeable of the data collectionprocess and how the collected data influences the quality of the DTM. Thus, therodman is key to the collection process.The surveyor is responsible for the processing, final checking, and validating of theDTM.HD-303.6TOPOGRAPHIC FEATURESTopography is defined as the graphic delineation of all natural and manmadefeatures of an area. Collect all topographic feature data within the project area.Where appropriate, elevations should be collected. For overhead utilities, identifythe ownership, pole number(s), and low wire elevation(s). Collect the majortopographic features of the area such as buildings, septic systems, existing roads,drainage structures, and utilities. The types of construction and descriptions forall buildings and existing roadway surfaces shall be noted. In addition, collect anyitem that may influence project decisions.HD-303.7EXISTING STRUCTURESAccurate depiction of existing structures is particularly important to the designprocess. Field information should completely define the structure andsurrounding terrain. Additional information should be collected to describe thecomponents of the structure (beam depths, pier heights, bridge seats, headwalls,abutments, wing walls, etc.). A written description of the structure should also bedocumented.HD-303.8PROPERTY LINE FEATURESAll property lines, easement lines, lease lines, and special agreement lines, as wellas KYTC permits and agreements, etc., within the limits of the project (and in someinstances in the general proximity) must be identified. All monuments andfeatures that aid in the description of property lines should be located.Other information to be collected to help locate property lines may include deeddescriptions, PVA maps, plats, and subdivision plans.The names of all property owners are to be collected as recorded in the deed book,along with the deed book and page numbers and acreage or square footage. 03/17Page 3 of 3

HD-304ChapterSURVEYINGSubjectUtility LocationHD-304.1OVERVIEWThe location of aboveground and underground utilities is a primary concern duringproject development. Complete and concise locations of existing utilities shall beobtained early in the design process. Utility company archives may not besufficient to identify all utilities within the project corridor.The quality level that is utilized in the location of existing utilities should be basedon the stage of development for a roadway project. During the corridor study todetermine potential alternatives, the use of existing records or verbal informationfrom utility companies typically will suffice.The quality level utilized in locating existing utilities should improve as alternativesare developed and their subsequent location refined. Location of utilities shouldinclude the horizontal position (and vertical position when appropriate) of theutility, the material of which it is composed, the size, and any other pertinent dataconcerning the facility.The following is a description of the differing quality levels of aboveground andunderground utility location. Quality level “D” and “C” apply to aboveground.Quality level “B” and “A” apply to underground utility location, but use level “D”and “C” for initial location.The quality levels for utility location are as follows: Quality Level D (QL D): Information derived solely from existing records orverbal recollections Quality Level C (QL C): Information obtained by surveying and plotting visibleaboveground utility features and by using professional judgment in correlatingthis information to Quality Level D information Quality Level B (QL B): Information obtained through the application ofappropriate surface geophysical methods to identify the existence andapproximate horizontal position of subsurface utilities03/17Page 1 of 3

SURVEYINGHD-304Utility LocationHD-304.1OVERVIEW (cont.)Note: Quality Level B data should be reproducible by surface geophysics at anypoint of the utility’s depiction. This information is surveyed to applicabletolerances and reduced onto plan documents. Quality Level A (QL A): Information obtained by the actual exposure (orverification of previously exposed and surveyed utilities) of subsurface utilitiesusing (typically) minimally intrusive excavation equipment to determine theirprecise horizontal and vertical positions, as well as their other utility attributesNote: This information is surveyed and reduced onto plan documents.Accuracy should be to applicable horizontal survey and mapping accuracy andshould be within 0.05 foot vertical.HD-304.2PROCEDURESProject Development Managers direct where Subsurface Utility Engineering (SUE)work is to be conducted. Locating existing utilities to a certain level should occuras early as the Pre-Design and/or Conceptual Design phase of a project wheneverthere are large concentrations of utilities or a major utility facility. At any stage ofdesign, the utility companies should be an integral part of the design process andshould be invited to key meetings to be advised of and consulted about impactsof the proposed roadway improvements to their facilities. Utility companiesshould also be invited to attend and provide input at public involvement meetings.The choice of alternatives for the proposed roadway should reflect thisinformation in an effort to first, avoid the utility conflict; second, minimize theeffect; and third, mitigate the conflict.The project team shall determine the quality level (QL) of utility locations for thevarious stages of project development conceptual design. QL A will be done asneeded, based on potential conflicts.To more adequately and expeditiously effect the location of utilities, the projectteam should specify in the advertisement for consultant services that theconsultant will be required to locate utilities to the differing levels dictated by theproject development stages. It may appear fiscally advantageous to place thebrunt of relocation costs on private companies, while avoiding publicly-ownedutilities, simply to avoid the direct cost of utility relocation by the Cabinet. Theultimate cost in time and money to the public should compel the designer toconsider all the impacts of utility relocation whenever decisions are maderegarding roadway location.03/17Page 2 of 3

SURVEYINGHD-304Utility LocationHD-304.2PROCEDURES (cont.)All quality level work shall be completed in accordance with Section 5: UtilityQuality Level Attributes as documented in CI/ASCE 38-02, the Standard Guidelinefor the Collection and Depiction of Existing Subsurface Utility Data by the AmericanSociety of Civil Engineers.HD-304.3DELIVERABLESThe utilities must be identified and located on plan documents. All undergroundutilities depicted shall be QL B unless the particular utility is labeled “QL C” or “QLD” (Exhibit 300-05). QL A is applicable only where direct observations of theexposed utility are made.A summary sheet will

specifications for the various survey activities discussed in this chapter. See HD-302 for GNSS survey control specifications. Whenever feasible, GNSS survey methods shall be used for establishing horizontal control. GNSS methods may be used to bring NAVD88 elevations to a project area provided 2nd Order accuracy (unless otherwise specified) can