Chapter 4 - Survey - Types

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Training Materials


Types of Surveys

  • The following survey types are the most commonly performed by MDOT. There are specialty surveys which may not fall into these categories. The requirements for specialty surveys will be determined on a project-by-project basis and implemented through the scope of services.

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Right of Entry

  • Act 115 of 1976 gives Surveyors the right of entry. Permission from the owner to enter their property is an MDOT requirement as well as a courtesy. Sample door-hanger notification cards are available upon request. Destruction of property is forbidden.
  • The use of paint should be minimal, if used at all on an MDOT project. Paint dots cannot be used as benchmarks, and do not need to be used to label benchmarks in the field. The use of paint on trees and sidewalks are considered destructive and are prohibited..
  • The use of lath and stakes to mark control points is permitted during the collection of field data. Once field work is completed, it is the responsibility of the Surveyor to remove all lath and stakes used.

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4.1 Control Survey

4.1.1 Purpose

General

  • All Project Control will be established according to the standards described in this manual.
  • The primary objective of a Control Survey is to establish positions (Northings, Eastings, and Elevations) in strategic locations that will govern any design survey work and construction survey work to follow. See 4.1.2.1 Control Location Guidelines for a list of ideal locations for control points.
Figure 4.1.1 Example Control Network

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4.1.2 Process

General Notes

  • Equipment used to establish project control must be tested and adjusted prior to beginning any project, and as needed throughout.
  • A record of the testing must be included in the notes.
  • The notes must reflect the date, instrument type, serial number, method of testing used and results.

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4.1.2.1 Control Location Guidelines

Project control monuments are recommended to:

  • Be positioned relative to NGS control or the Michigan Spatial Reference Network (CORS).
  • When required, Primary Control points should be set, prior to other control establishment, as an intervisible pair, preferably perpendicular, to the project route to improve project geometry.
  • Intermediate Control should be positioned along the project path to provide check points for RTK rover work / total station work at regular intervals.
  • Have a clear view of the horizon above 15 degrees if used for GPS observations.
  • Be located on stable ground.
  • Be readily accessible.
  • Be located off the traveled portion of road but within the road Right of Way, or located on public property.
  • Be set in anticipation of any future tree or shrub growth.
  • Be set in order to avoid tall structures which could cause multipath.
  • Be set to avoid radio towers, power transmission lines, and other sources of RF interference.
  • Be set so they are intervisible for use with conventional survey methods.
  • NOT be located in medians or ramp gores, when construction is imminent for those areas.
  • Be located on back slopes 1-5 feet above the centerline elevation in cut sections.
  • Be located 10-15 feet from the edge of pavement in fill sections.
  • Be set at a location which ensures the safety of surveyors and others.

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4.1.2.2 Witnessing Control

  • Witnesses are required for Primary and Intermediate horizontal and vertical project control to help find design control during the construction phases.
  • Witnesses will be measured to the nearest foot and the magnetic bearing recorded to the nearest five degrees.
  • Witnesses must be within 200 feet of the point referenced.
  • A minimum of four witnesses will be required for each horizontal and vertical control point if no stationing is established for a project; otherwise, three witnesses and a station and offset will suffice.
  • An acceptable witness will be a solid, permanent, physical object such as edge of asphalt, centerline, building corner, sign post, or a nail with tag or shiner in a tree or utility pole.
    • Stakes and hubs are not acceptable witnesses. When no stationing is provided, the point’s location must be sufficiently described to recover easily.

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4.1.2.3 Primary Control

  • The purpose of the Primary Control is to act as a basis of horizontal and vertical components to be perpetuated throughout the design and construction phases. Primary Control monuments will be used as base station locations if RTK methods are employed, and can be used for mapping purposes. When properly done, a Primary Control monument can last more than 30 years.
  • Primary Control consists of a metal disk oriented north, set in poured concrete as defined in Figure 4.1.2.1.
  • The Primary Control monuments will be set in intervisible pairs at the spacing of 2640 to 5280 feet apart. Each pair will be located 3-5 miles apart along the length of the project.
  • At the direction of the MDOT Survey Consultant Project Manager or the MDOT Region Surveyor:
    • At least two Primary Control monuments will be set on each project unless Primary Control exists from a neighboring project.
    • Once locations are determined, MISS DIG must be contacted for utility location prior to point construction.
    • Once established, each Primary Control point must be witnessed as described above in Section 4.1.2.2 and appear in the field notes and the Survey Info Sheet.
    • A Monument Establishment Form must be completed for each Primary Control point established
    • Freeway Projects & Rural Arterial Projects will apply the rules as written in this section.
    • Urban Arterial Projects will require one pair if the pair are intervisible. Two pair will be required if no intervisibility is achieved.


Figure 4.1.2.1 Primary Control Monument

The concrete monument is normally poured in place in a hole dug in the ground, using a top form only. The hole is dug to a depth of 5' (sufficient to extend below the frost line) with either a square or circular cross section (depending on shape of top form used, and about 12 to 14 inches or more in diameter). The bottom of the hole is enlarged about 2 inches in radius tapering upward for about 1/2 foot in order to make the bottom of the monument bell-shaped. The concrete is poured and tamped in the hole until a level is reached where the top form when set on the concrete will either be flush or will protrude from 2 to 6 inches from the ground. The form should be fitted into the hole before the 1 foot of concrete is poured in order to avoid any shoulders or mushrooming effect near the top of the monument which might afford purchase for frost action. The pouring, tamping, and back-filling are completed, and the top of the monument smoothed off and beveled with a trowel. The disk is then pushed into the center of the concrete monument and recessed slightly to elude prying out the disk.

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4.1.2.4 Intermediate Control

  • The location of Intermediate Control will supplement the Primary Control. The purpose of Intermediate Control is to provide a framework for design mapping, photo control and construction activities.
  • Intermediate Project Control consists of semi-permanent marks set during the survey for a project.
  • These control points should hold horizontal location within 0.05 feet over a time span of 10-15 years.
  • Intermediate Control points should not be established in locations where the Primary Control point will suffice for mapping or construction activities.
  • Once established, each Intermediate Control point must be witnessed as described above in Section 4.1.2.2 and appear in the field notes and the Survey Info Sheet.
  • Intermediate Control also includes the points set for highway alignment.
    • An Intermediate Control point is made up of a #5 rebar rod 36 inches in length with a survey cap stamped “TRAVERSE POINT” or similar phrase.
    • Intermediate project control is covered in Section 7 of the MDOT Design Survey Manual.
  • FREEWAY will require an Intermediate Control point to be set every 650-1320 feet apart from each other and any Primary Control and must be intervisible.
    • Benchmarks must be set every 300-1500 feet apart.
  • RURAL ARTERIAL will require an Intermediate Control point to be set every 350-900 feet apart from each other and any Primary Control and must be intervisible.
    • Benchmarks must be set every 300-900 feet apart, preferably at high and low points of vertical curves.
  • URBAN ARTERIAL will require an Intermediate Control point to be set at least every 300 feet in grassy areas and must be intervisible.
    • Benchmarks must be set every block, with no more than 600 feet apart.

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4.1.2.5 Vertical Control

  • Preferred Benchmarks consist of chiseled squares in concrete abutments, headwalls, substantial concrete foundations, Top of Manhole Casting, or other immovable objects.
  • Benchmarks may be set on top of anchor bolts, however chiseled marks of any kind in galvanized sign bolts are not acceptable due to the destructive nature and corrosion it subsequently causes.
  • Use of fire hydrants and spikes in trees is discouraged.
  • Spikes in sign posts and power poles are not acceptable.
  • In rural areas it may be necessary to use alternative benchmarks. Contact the MDOT Survey Consultant Project Manager or the MDOT Region Surveyor to discuss options.
  • Once established, each Vertical Control point must be witnessed as described above in Section 4.1.2.2 and appear in the field notes and the Survey Info Sheet.

Unless otherwise specified, leveling will be performed using a conventional method for all Scenarios.

Conventional Method

Following is a preferred method for conventional leveling associated with third order leveling:

  1. Locate at least two NGS first or second order benchmarks, checking within tolerance, for Road Design and Structure Survey categories. Ideally, the NGS benchmarks should be situated with two on each side of the project.
  2. All turns not occupying a benchmark must be made on turning turtles weighing at least 16 pounds each and/or turning pins. Turning pins are acceptable when they comply with Figure 4.1.2.3 below. If turtles are used or if equipment does not look like the figures provided, contact the Survey Consultant Project Manager with a photo of the proposed devices for approval.
  3. All loops must be closed. For a closed loop to exist, it must start at a known elevation and end at a known elevation. The error of closure must not exceed 0.05 feet times the square root of the distance leveled in miles, or 9.469 ppm.
  4. Start on an NGS benchmark.
  5. Loops must not exceed 5 miles in length. If no existing station exists within 2.5 miles, a temporary benchmark must be set and the loop be closed back to its original point.
  6. This procedure is repeated until at least one primary monument is reached and looped to its beginning. The procedure is repeated until a second NGS benchmark is reached.
  7. Pick up at the other end of the project and repeat the procedure outlined in 5 and 6 above.
  8. If additional NGS benchmarks are found near the middle of the project, they should be tied in to primary monuments using the same procedure.
  9. Pick up at a primary point with a known elevation and continue the process through the Intermediate Control and tie into all Primary Control with known elevations.
Order First First Second Second Third
Class I II I II
Section Running DR or MDS DR or MDS DR DR DR
Difference of forward and backward sight lengths never to exceed:
per setup (ft) 6.6 16.4 16.4 32.8 32.8
per section (ft) 13.1 32.8 32.8 32.8 32.8
Maximum sight length (ft)l 164.0 196.9 196.9 229.7 295.3
Minimum ground clearance of line of sight (ft) 1.6 1.6 1.6 1.6 1.6
Even number of setups when not using leveling rods with detailed calibration Yes Yes Yes Yes ...........
Determine temperature gradient for the vertical range of the line of sight at each setup Yes Yes Yes .......... ..........
Maximum section misclosure (in) 3*SQRT(D) 5*SQRT(D) 6*SQRT(D) 8*SQRT(D) 12*SQRT(D)
Maximum loop misclosures (in) 4*SQRT(E) 5*SQRT(E) 6*SQRT(E) 8*SQRT(E) 12*SQRT(E)
Δ h1 - Δ h2 for one setup not to exceed (in) for MDS procedure 0.01 0.01 0.02 0.02 0.05
Use multiple reading option to obtain each observation - minimum number of readings 3 3 3 3 3

Figure 4.1.2.2 Electronic Digital/Bar-Code Leveling Systems (Modified) 

   in = inches
   ft = feet
   D = Shortest one way length of sections in Miles
   E = Length of loop in Miles
   DR = Double Run
   MDS = Modified, Double Simultaneous Procedure
  • Please note:
    • A loop should be completed the same day it is started.
    • Leveling error of closure will be distributed throughout the system by means of a least squares adjustment program acceptable by the MDOT Survey Support Unit. The adjustment is to be made only if the error of closure of the unadjusted observations is less than or equal to the above standards. Errors greater than required limits will require re-leveling the affected loops in the opposite direction or extending the loop to the original published bench mark. The leveling must be adjusted between all published bench marks for which the accuracy criteria is met.


Figure 4.1.2.3 Leveling Turning Pin With Driving Cap

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GPS Method for establishing Vertical Control
  • GPS can be used for vertical control establishment with the approval of the Survey Consultant Project Manager or Region Survey Manager when NGS benchmarks are not close to the project. The following method will be used:
1. Locate four second order or better NGS benchmarks which can also be observed using GPS that surround the project.
2. A four hour simultaneous observation must be made consisting of all four NGS benchmarks and at least two Primary Control monuments. This can be done at the same session for horizontal positioning.
3. RINEX files or OPUS results for all stations will be reported to the MDOT Survey Consultant Project Manager or MDOT Region Surveyor reported with the following table:
4. Additional level runs can be conducted using the conventional method described above prior to approval of the primary elevations. No more than two elevations can be determined using this method. No mapping can start until primary approval is made by the Survey Consultant Project Manager or Region Survey Manager.
Station Name ARP Record Elevation Measured Elevation Delta Adjusted Elevation
NGS #1
NGS #2
NGS #3
NGS #4
Primary #1
Primary #2
  • When the above procedures are followed, the resultant elevations will meet or exceed third order vertical control.
  • Leveling error of closure will be distributed throughout the system by means of a least squares adjustment program acceptable to the Supervising Land Surveyor of MDOT Survey Support Unit. The adjustment is to be made only if the error of closure of the unadjusted observations is less than or equal to the above standards. Errors greater than required limits will require re-leveling the affected loops in the opposite direction or extending the loop to the original published bench mark. The leveling must be adjusted between all GPS derived bench marks for which the accuracy criteria is met.

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4.1.2.6 Establish State Plane Coordinates On Control

Primary Horizontal Control

  • The Project Surveyor must insure that each horizontal position determined by the survey is correctly located in the project’s coordinate system. Measurements may be made by ground traverse with conventional surveying instruments suitable for the purpose, or with GPS equipment. The control network should be measured and adjusted before computations are made for other purposes and prior to mapping.
  • Primary Horizontal Control requires two (2) static observations of no less than two hours and no more than 4 hours as a minimum, with the observation time depending on the distance to the CORS sites. The following is a guideline for calculating the observation time:
Distance from farthest CORS (in miles) Minimum Observation Time
Under 25 2 hours
25 – 43 3 hours
44 and over 4 hours
  • Each Primary Control pair should be observed simultaneously. An NGS horizontal monument being considered for use as a Primary Control point must also be tied into the primary network with a static observation.
  • Processing of vectors, relating the Primary Control to the NSRS, may be done using OPUS. Elevations obtained from the leveling procedure must be used and held fixed on all Primary Control monuments. An OPUS solution that meets the criteria outlined in Chapter 8.3.3_OPUS_Procedure are acceptable to be used for the adjustment of Intermediate Horizontal control. If blunders exist or any point does not meet the specification, re-observe the data.


Intermediate Horizontal Control

  • Intermediate Horizontal Control will be positioned typically with GPS, using either of two approaches to network configuration, radial or non-radial.
  • A radial network consists of observations that are tied to base stations without multiple interconnections; each new point is connected directly to at least two controlling stations (NGS and/or MDOT Primary).
  • A non-radial network consists of multiple interconnected closed figures, with each station tied directly or indirectly to at least two controlling stations.

Note:

  • If GPS is used to determine positioning of Intermediate Control, please refer to the GPS Section below. If classical traversing is used instead of GPS to determine positioning of Intermediate Control, refer to the Traversing Section below.


GPS

  • When using GPS to establish intermediate project control, the following guidelines shall be adhered to.
  1. GPS observations shall conform to the specifications for intermediate control surveys and meet standards consistent with intermediate control traverses.
  2. GPS intermediate horizontal control surveys shall be tied into three known horizontal control points and four known vertical control points published by NGS or established by primary horizontal/vertical control surveying methods.
  3. GPS horizontal control shall form a network with at least 20% of all points being occupied twice. Points less than 1 mile apart shall be occupied simultaneously.
  4. Minimally constrained and fully constrained least squares adjustments shall be performed. Vectors containing normalized residuals of 2 or higher in any component shall be removed and the network readjusted. Two vectors shall remain for each intermediate project control point.
  5. Maximum standard deviation for any coordinate shall not exceed +/-0.01 feet. The radius of the circle of uncertainty at the 95% confidence region shall not exceed 0.07 feet.
  6. Final coordinates shall be derived from a fully constrained least squares network adjustment holding three primary control horizontal points and four vertical control points as fixed.


Traversing

  • When using the traverse method for establishing intermediate project control, the following guidelines shall be adhered to.
  1. Intermediate control traverses are to be closed and adjusted between two or more pairs of primary control points with known coordinates.
  2. All intermediate control points are either part of the traverse (occupied) or measured from at least two points that are part of the traverse. Open ended traverses are not acceptable.
  3. Distances between traverse points should not be less that 300 feet.
  4. No distance shall be adjusted by more than a ratio of 50 parts per million of that distance nor shall any angle be adjusted by more than 5 seconds.
  5. Targets shall be attached to tribrachs and mounted on tripods.
  6. Horizontal distances shall be measured twice, once in a forsight mode, once in a backsight mode.
  7. Horizontal angles shall be measured twice in the direct position, twice in the reversed position.
  8. Zenith angles shall be measured once direct and once reversed.
  9. Intermediate control traverses shall be analyzed and adjusted by a suitable least squares adjustment program acceptable to the Supervising Land Surveyor, MDOT Design Division.


  • For either of these approaches to network configuration, GPS observation type will be static or rapid-static, with a minimum 30-minute simultaneous observation time between receivers. If using the radial approach, RTK is also acceptable, see Chapter 8.3 RTK GNSS.
  • NGS and/or MDOT Primary Control stations will be the basis for all Intermediate Horizontal Control. No new station in the network must be outside of a closed loop; only an NGS or MDOT Primary Control station may have a single line connected to it (in that case the adjusted single line must be the result of at least two occupations). In any case the controlling stations must essentially surround and enclose the new Intermediate Control network.


Network configuration approaches:

  • All controlling NGS and/or MDOT Primary Control stations, and all new Intermediate Control stations, will be independently observed at least twice; a minimum of 20% will be independently occupied at least three times. For occupations of any given NGS and/or MDOT Primary Control station, a repeat occupation can only occur after a minimum of 4 hours has elapsed from the prior occupation, using a different instrument setup. The final network must ensure that all points have at least two vectors from independent sessions connecting them to the rest of the network.

Radial network -

  • Subsequent point occupations cannot occur until a minimum of 4 hours has elapsed from the prior occupation of any one point in the network.

Non-radial (interconnected) network

  • A subsequent occupation of any given point may occur at any time, but the subsequent occupation cannot occur without changing the receiver setup. This includes using a distinctly different height of instrument when using conventional tripods, manually recorded, to verify that the independent setup took place. Use of fixed height tripods is encouraged, therefore, the setup verification / change comes down to reaffirming that the level bubble is still within tolerance at the beginning and end of the session.
  • All observed vectors may be processed but only NON-TRIVIAL vectors must be used in the adjustment. The “trivial vector” in a GPS observation session can be any one vector which would close a simultaneously occupied loop; the number of independent vectors is n-1, where n equals the number of receivers being used in the simultaneous observation session.
  • To understand the concept of independent and trivial vectors, it is important to keep in mind the fact that baseline vectors are not true observations; they are 3D inverse solutions, derived from calculated 3D positions. The actual observation is between the GPS constellation and the receiver, therefore simultaneous occupations result in baseline vectors derived from identical (more or less) observation conditions, most of which are beyond the control of the surveyor.

Positional tolerance:

  • The 0.07 foot positional tolerance (95% confidence level) specified in the MDOT Design Survey Manual for Intermediate Horizontal Control may be difficult to achieve under some circumstances (near buildings, tree cover, etc.); it may be necessary to augment the GPS network with 3D conventional total station observations to achieve that level of accuracy. If that approach is taken, the least squares adjustment must simultaneously adjust both types of 3D observations, at which point great care must be taken to properly integrate appropriate weighting of conventional observations into the solution.

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4.1.2.7 ADJUSTMENT OF DATA

  • The following allowable error should be taken into account for any adjustment:
    • Centering error cannot exceed 0.02 feet
    • Baseline measurement error cannot exceed 1:20,000, or 50 ppm


  • Three types of adjustment reports are required.
    • The first adjustment will process all Primary Control, holding the OPUS results for two points the farthest away from each other. No CORS site data is required in this adjustment, but the OPUS results and the CORS RINEX files must be submitted. Results of the remaining Primary Control will be compared to the OPUS results.
    • The second adjustment will process the Intermediate Control in a minimally constrained adjustment. This adjustment will hold one Primary Control point fixed, and will process the baselines to the primary and intermediate points. Elevation of the Intermediate Control should be compared to the elevation obtained through the leveling procedures before constraining to the leveled values. Analysis of comparative EDM observations should also occur prior to the final adjustment.
    • The third and final adjustment is a fully constrained adjustment of the Intermediate Control holding fixed the position of as many Primary Control monuments as needed. The maximum standard deviation of a single coordinate must not exceed 0.10 feet. Any differences over 0.05 feet must be addressed in the Surveyors Report. The leveled elevation must be the reported elevation. If the results are unsatisfactory, re-observe the data.

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4.1.2.8 EDM CHECK OBSERVATIONS

  • Distances between Primary Control points must be observed by EDM for each pair. These observations must be reported in a concise format showing the GPS grid distance, combined scale factor, EDM ground distance and the adjusted EDM grid distance. A recommended table is as follows:
Point Designation Average Combined Scale Factor (ACSF) Measured GPS Grid Distance (GPS) Calc. Ground Distance = GPS / ACSF Measured EDM Ground Distance Δ Distance
33304 to 33305 0.999876554625 600.77 600.84 600.89 0.05
33304 to 33306 0.999876553875 772.94 773.04 772.99 0.05

Error resolution must be described in the Surveyor’s Report.


TEMPORARY CONTROL

Temporary control can be used on MDOT projects within the following guidelines.

  • Temporary benchmarks can be a keel square on a concrete step or a paint spot on the RIM of a catch basin or manhole. They must be defined in field notes as temporary in nature. They are to be used in large bench loops when the distance is great. Hubs are NOT acceptable as temporary benchmarks or turn points.
  • Temporary control points can be an 18 inch #4 rod or 5 inch 60d nail in the ground, or a MAG-NAIL in asphalt. These points can be set for various reasons, including additional topo in areas where RTK cannot observe locations accurately. Temporary control points can be set using conventional survey methods and may be removed after use. Generally these points are established from adjusted control for temporary use. If temporary control is to be used after 5 calendar days, it will need to be re-observed for its location. Hubs and tacks are acceptable for temporary horizontal control with a limit of one day.


SUMMARY OF STANDARD PARAMETERS FOR CONTROL TASKS

Description Material/Precision
Precision of scale factors: 12 digits to the right of decimal
Witness measurements: Nearest foot, nearest 5 degrees
Primary Control monument material: Concrete w/metal cap (see Figure 7-3 in Survey Manual)
Intermediate Control monument material: #5 rebar -36” long w/cap “TRAV POINT”
Temporary control material: #4 rebar; 5” 60d nail; Mag Nail
Temporary benchmarks: see discussion above
Primary Control pair spacing: 3 to 5 miles
Primary Control intervisible pair spacing: 2640 to 5280 feet
Intermediate Control spacing: 650 to 1320 feet (Freeway)
350 to 900 feet (Rural Arterial)
300 feet and intervisible (Urban Arterial)
Primary GPS observation time from CORS: See table above
Primary Control - max S.E. (2s): 0.05’ (each coordinate)
Intermediate Control max S.E. (2s): 0.07’ –average; 0.10’ max (each coordinate)
Setup max centering error: 0.02’
Setup max H.I. error: 0.01’
Baseline max measurement error: 50ppm
Benchmark material: On concrete structures (see Survey Manual)
Benchmark spacing: 300 to 1500 feet (Interstate)
300 to 900 feet (Rural Arterial)
Less than 600 feet (every block) (Urban Arterial)
Benchmark Loop –max loop closures: 0.05’*sqrt(Miles) (9.469ppm)

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4.1.3 Requirements

Horizontal Control Deliverables


Vertical Control Deliverables
  • The surveyor must develop a listing of bench marks which includes name of company, month and year of collection and datum in the header. A comment should appear on the list disclosing the source of elevations. Specific information for the benchmark includes designation, elevation, and description of what was found or set. Benchmark descriptions must include the type of mark, any stamping on the mark, coordinates, and stationing and offset from an alignment. Location of benchmarks must be determined by measurement from primary or intermediate horizontal control points. Primary Vertical Control / NGS benchmarks not within project limits, but used to control the survey, must appear in the list with a description and elevation. All benchmarks held fixed in the final adjustment should be designated as such in the benchmark list and Survey Info Sheet. GPS-derived NAVD88 elevations should be noted as such, on the Survey Information Sheet, when used as the elevation source.

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4.2 Alignment / Right Of Way Survey

4.2.1 Purpose

The purpose of a Right of Way survey is to accurately determine the legal boundary lines of the MDOT right-of-way. These surveys typically correspond with the retracement of the legal alignment along a given section of roadway. MDOT defines a road alignment as a series of tangents and geometric curves incremented in 100 foot stations that define the location and direction of the roadway or proposed roadway improvement.


In practice, the terms 'alignment' and 'centerline' are frequently used interchangeably; though when standing alone these terms are generic in nature and are not synonymous. When preceded by a descriptive term such as 'Survey' or 'Legal', however, it is generally assumed that the term 'centerline' is a reference to an alignment. In the past, and up to the 2012, these terms have often been used synonymously. As illustrated by the definitions in Chapter 6, this should not be the case. Legal alignments, as implied by their name, are intended to define the legally correct location of Rights-of-Way, parcels, easements, etc. that are either explicitly or implicitly tied to them by statute, description or instrument of conveyance. In this way legal alignments are very similar in standing to Government Section Lines since they control the location of the property described from them.

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4.2.2 Process

4.2.2.1 MDOT Alignment Standard(Annotation)

Alignments will be designated in CAD only as legal or non-legal by the surveyor/engineer. Differentiation and perpetuation of existing alignments will be done through annotation. Design alignment deliverables will be designated using the current release of the MDOT Workspace and on the appropriate levels. The current Workspace can be found in Chapter 2.2.1 MDOT Workspace.

It is of primary importance that MDOT alignments are properly perpetuated. Relevant alignments from jobs in the project area must be researched, retraced and appropriately tied to one another and the project control. These ties must be shown on the alignment plan sheet(s) and referenced in the surveyor’s alignment reports. Multiple alignments may be required to properly describe all situations within the project area. All alignments must be annotated with the description and year of any previously established alignment which is being retraced, as well as the year of the current survey retracement. Any new alignment which is established and is completely independent from other alignments must be annotated with the current year it is established.


Annotation must be consistent with the guidance document released as an attachment to Alignment Chain Naming Convention.

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4.2.2.2 Alignment Certification

When a legal property survey is required for the purpose of describing Right of Way, the final alignment data must be certified by a Professional Surveyor, within the survey report certification language, as follows:


“I hereby certify that [list annotated names of all alignments for project] have been developed from [list all sources used, including survey data collected, previous plans, deeds, etc.] and that accuracy standards are in accordance with current MDOT Design Survey Standards. This/These alignment(s) correctly represent(s) the existing conditions at the time the survey was completed.”'


See 10.2 Deliverable Naming, Content, and Format Requirements for more information.

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4.2.3 Alignment Requirements

It is of the utmost importance that the Surveyor discusses the alignment requirements with the MDOT Survey Consultant Project Manager or MDOT Region Surveyor to determine the type or extent of alignment data required for a given project. This discussion should take place prior to the submission of a price proposal. If there is any question with regard to what may be needed for alignment, the MDOT Survey Consultant Project Manager or MDOT Region Surveyor should be contacted.


The surveyor must make sure that new alignment angles and distances reflect the accuracy with which the underlying control was established. Generally, this means bearings should be rounded to the nearest second and distances defined to the nearest 0.01 feet.


If establishment of alignment monumentation is required for the project, at least two alignment control points must be found or set and witnessed on the points of curvature and tangency. The points on tangents must be intervisible and not be more than 3000 feet apart. When structures hinder the line of site, an alignment point must be set on line at least 200 feet from the Structure on both sides. An 18 inch #5 or larger rebar may be set in the hard surface road protected by a monument box with cover. Offsets, ideally on the Right of Way, may be used with authorization obtained from the MDOT Survey Consultant Project Manager / MDOT Region Surveyor before their physical location is staked in the field.


The alignment point must be double tied from a minimum of two Primary or Intermediate Control points. The standard deviation between the two locations of these alignment points should not exceed 0.10 feet. Since a legal alignment point is considered a property controlling corner, a Land Corner Recordation Certificate must be filed showing its relationship to the nearest section line by bearing and distance. The job number and control section information should be included on the PA 74 of 1970, as amended.


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4.3 Design Survey (Topographic)

4.3.1 Purpose

The purpose of performing a topographic survey is to map a site for the depiction of man-made and natural features that are on, above, or below the surface which will affect the design of the particular highway system. From this survey, planimetric maps, topographic maps, and a digital terrain model will be developed to show what existed on-site at the time of the survey. The project folder will contain sections for all surface topography (planimetric data), elevations, surface utility locations, and drainage, both surface and underground. The road design engineers will use the digital data for much of their design work. All files must utilize the same coordinate base. All mapping deliverables turned in must contain a statement similar to which follows, certifying map accuracy signed and sealed by the project surveyor.

I hereby certify that this map has been developed from survey data collected, and that accuracy standards are in accordance with the MDOT Survey Standards of Practice. This map correctly represents the existing conditions at the time the survey was completed.

The above statement can and should be modified to fit project conditions.

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4.3.2 Vertical and Horizontal Control

Control points that will be used for topographic mapping must have a standard of accuracy of 0.07 feet or below at the 95% confidence level.

Elevation data will be obtained as needed for project design, quantity computations and drainage studies. As a general rule, there should not be more than 66 feet between random observations to obtain elevations. The accumulated standard error for ground elevations should be no greater than 0.1 foot. All hard surfaced roads, curbs and sidewalks and water surface elevations must be recorded to the nearest 0.01 foot. The relative error between adjacent elevations must have an accumulated standard error of no more than 0.02 foot for hard surface measurements. If the total station method is used, instrument and target heights must be measured to the nearest 0.01 foot and recorded. Sights must be taken on targets on prisms. Distances for observations taken to determine hard surface elevations must not exceed 600 feet. No distances for any topographic data collection must exceed 1200 feet.

When doing mapping field work, all horizontal and vertical control must be checked into as random measurements with the designation recorded. The difference between mapping check coordinates and previously adjusted coordinates must not exceed 0.05 foot in x, y, or z.

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4.3.3 Feature Identification

All features within the site will be identified and their position located on the ground. Research of all pertinent documents will include as-built and design maps within MDOT, pertinent maps found within the municipal offices, and information extracted from legal research for lands within and adjacent to the site. Feature identification (description) should include, but must not be limited to: tree species and size (trunk diameter measured 4.5 ft above the ground); culvert type, size and condition; material description (bit over concrete); building type and address (2 story frame, house number); etc. Groups of trees, woods and brush should be classified as shown in Table 12.1.

Table 4.3.1 Classification Table for Trees, Woods and Brush

Classification Clearing Size Average Spacing of Trees (Center to Center)
Light Medium Heavy
1st Class 37" Diameter or Larger 15' or More 10' to 15' 10' or Less
2nd Class 19" to 36" Diameter 20' or More 10' to 20' 10' or Less
3rd Class 8" to 18" Diameter 10' 3' to 10' 3' or Less
4th Class 7" Diameter or Less and Brush One Half Covered Two Thirds Covered Completely Covered

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4.3.4 Planimetrics

Planimetric features are usually required for a road improvement to be designed. All features that might affect the design must be shown on a complete planimetric map prepared from field survey measurements. All maps must utilize the current version of the MDOT Workspace which includes the correct levels, cells, linestyles, etc. No additional (Non-MDOT) Feature Codes or symbols are to be used. Points and lines are to be displayed according to MDOT specifications in Plans Preparation Guidelines.


The map must be in digital form. Deliverable drawings must use the appropriate MDOT seed file. The digital file will also contain control, alignment and type, and property data. The map must present the data in a clear and legible manner. Street names as they appear in the field should be labeled for all cross roads. Multiple road names should also appear. Overlapping text, incorrectly drawn curves, crossing lines, etc., should be corrected prior to submission.


If the survey is being completed for MDOT design squads, all maps must utilize the most recent MDOT Design Division Cell Library. No additional symbols will be used. Symbols must be sized appropriately for the scale of the drawing. Points and lines are to be displayed according to MDOT specifications in Plans Preparation Guidelines. The map must be in digital form. Microstation drawings must use the appropriate MDOT seed file. Table 4.3.2 shows the proper seed files for state plane coordinate projects.


If the survey is being completed for consultant design it is highly recommended that the project surveyor communicate with the project designer to obtain formats and data structures necessary to facilitate the software interface.


Structure surveys are often required, and must conform to these standards with the following additions:Bridges, culverts, retaining walls and other structures require precise relative measurements. All structure dimensions are recorded to 0.01 foot. Bridge dimensions may be recorded on new field sketches or hand written on copies of construction plans. Elevation view sketches should be included and annotated appropriately. Specific information will be requested by the bridge unit. Photographs will be taken only if requested and labeled with control section, project number, data


Table 4.3.2 - MDOT Seed Files: Feet 1983 Datum State Plane Coordinates

North Zone Central Zone South Zone
3D Seed Seed_North_3D_MDOT.DGN Seed_Central_3D_MDOT.DGN Seed_South_3D_MDOT.DGN
2D Seed Seed_North_2D_MDOT.DGN Seed_Central_2D_MDOT.DGN Seed_South_2D_MDOT.DGN
Global Origin X 24,000,000 17,000,000 11,000,000
Y 0 0 0
Z -2,147,483.65 -2,147,483.65 -2,147,483.65
Working Units Master Units MU 1 1 1
Sub Units SU 1000 1000 1000
Positional Units PU 1 1 3

and content. The project surveyor must insure that all required information is presented in a form easily accessed and understood by the designer.


Electronic field data must include all topography around the structure to the limits described in the request for survey. The resulting terrain data for the approach design must include the terrain beneath the bridge deck, but must exclude the deck itself.


See Chapter_10_-_Deliverables for the standard naming and required files that need to be submitted.

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4.3.5 Terrain Elevations

Elevation data will be obtained as needed for project design, quantity computations and drainage studies. As a general rule, there should not be more than 100 feet between random shots to obtain elevations. Elevations of ground surfaces (dirt) should be recorded to the nearest 0.01 feet. The accumulated standard error for ground elevations should be no greater than 0.10 feet. All hard surfaced roads, curbs and sidewalks and water surface elevations must be recorded to the nearest 0.01 feet. The relative error between adjacent elevations must have an accumulated standard error of no more than 0.05 feet for hard surface shots. If the total station method is used, instrument heights and target heights must be measured to the nearest 0.01 feet and recorded. Sights must be taken to targets on prisms. Distances for shots taken to determine hard surface elevations must not exceed 650 feet. No distances for any topographic data collection must exceed 1300 feet.


When doing mapping field work, all horizontal and vertical control must be checked into as random shots with the designation recorded. The difference between mapping check coordinates and previously adjusted coordinates must not exceed 0.05 feet in x, y or z.


When requested, the surveyor must produce a digital terrain model (DTM) of the project site. Break lines and high/low points must be used to make the model an accurate representation of the shape of the ground. In many cases cross sections at a set interval will not yield an accurate representation of the terrain. Careful attention should be given to observation of the terrain as it breaks in the field. Building interiors must be excluded from the DTM. The surveyor must examine the model for accuracy and completeness. A contour map of the site will be produced from this model. The project surveyor must certify the accuracy of the contour map. The map should show the alignment and horizontal control as a reference.


When terrain elevations are obtained to supplement photogrammetric or LiDAR mapping, both the ground survey and the photo / LiDAR mapping must use the same horizontal and vertical control. A digital terrain model and contour map must be produced as described above but limited to hard surface observations and obscured areas.

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4.4 Bridge/Structure Survey

4.4.1 Purpose

A bridge survey is required whenever a proposed bridge or the reconstruction of an existing bridge is to be incorporated into the design of a roadway. These kinds of surveys are very different from the conventional route surveys, although they may incorporate route design principles within their structure. The main function is to locate the bridge such that it meets the roadway on either end in a manner that facilitates safe vehicular traffic flow.

4.4.2 Process

Reserved

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4.4.3 Requirements

Reserved

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4.5 Hydraulic Survey

4.5.1 Purpose

The purpose of a hydraulic survey is to capture field data that can be used by the design team for bridge and culvert design characteristics. It is critical that the surveyor work with the MDOT Hydraulics Unit before undertaking such a survey to determine the extent of the data that needs to be collected. If no control is available in the site area the surveyor will be required to bring survey control onto the site for proper referencing of the survey. Part XIII describes the duties of the surveyor in a hydraulic and hydrologic survey.

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4.5.2 Process

Reserved

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4.5.3 Requirements

Reserved

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4.6 Certified Surveys for Real Estate Acquisition

4.6.1 Purpose

The purpose for the development of concise and standardized surveys as part of the acquisition process is founded in the desire to leave footsteps that can be followed by landowners impacted by MDOT’s acquisition process, to supplement MDOT’s asset management plan with real estate information and to comply with Public ACT 132 of 1970, as amended – Certified Surveys ACT. This section of the manual sets forth the process and requirements for acquisitions of permanent Right-of-Way (R.O.W.) by MDOT, comprised of the following primary elements:

  • Accurate parcel locations relative to project coordinates for use in the design process
  • Drawing and descriptions, compliant with the Certified Survey ACT (Public ACT 132 of 1970, as amended) including the following:
    • The surveyed boundary of the acquisition parcel with corners found and/or set.
    • The proposed area to be acquired.
    • The alignment(s) related to the taking.
    • Monumentation placed at the location of the proposed new R.O.W. limits.

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4.6.2 Process

Development of Certified Surveys for Real Estate Acquisition requires a close working relationship and collaboration amongst the Project Manager, Designer, Region Real Estate Personnel, Consultant Survey Manager / Region Surveyor and the Project Surveyor (“Surveyor”). A process diagram shows the interactions and steps described below as a workflow.Certified Survey Workflow

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4.6.2.1 Property Information Provided to Surveyor

When it is determined that permanent R.O.W. is required within the current project limits, parcel ownership research information for every parcel potentially affected will need to be provided to the Project Surveyor appointed the task of creating the Certified Survey(s). The Design Engineer, in collaboration with MDOT Real Estate Staff, Surveys, and the Project Manager, will deliver all of the information gathered for each parcel potentially requiring the creation of a Certified Survey. Parcels acquired as "total takes" will typically not require a Certified Survey. Parcel ownership research information may include the following:

  • Property owner name/address/phone number
  • Tax Assessment Description
  • MDOT Parcel Number (if known)
  • Title commitment
  • Vesting deed
  • Any pertinent neighboring descriptions/deeds
  • Previous Surveys (if obtained)

In addition to parcel ownership research information, the project base plan CAD drawing(s) depicting the area to be acquired will be provided. The plans should include the following information from the design survey and design:

  • Proposed preliminary design including approximate R.O.W.
  • All alignments
  • All survey monumentation, R.O.W. lines, and parcel lines

Utilization of ProjectWise links to the documents and the CAD files is required. Additional information necessary to complete the Certified Survey that was not collected by MDOT will be the responsibility of the Surveyor creating the Certified Survey.

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4.6.2.2 Determine If and How Parent Parcels Are Affected

To determine if the parent parcel is affected, the Surveyor and Real Estate Staff will review the base plans along with tax maps, tax descriptions, deeds, title work, etc. to generate a list of parcels impacted by the need for permanent R.O.W. During this step it may be necessary for the Surveyor to plot approximate non-legal parcel lines, if not previously established in the design survey. If the location of the designer’s proposed permanent R.O.W. call is close to the location of a parcel boundary line, include that property in the list of parcels that could be affected by the project. A spreadsheet or document will be generated listing the parent parcels tax id, parent parcel owner name, phone number, address, and any other pertinent information. A tax map is recommended, if available, with the parent parcels marked/highlighted. The Surveyor and Real Estate Staff will both agree to the list of parent parcels affected. Using this list, Real Estate staff can then order title work for the affected parent parcels if the title work has not already been obtained. Once the Real Estate Staff receives the title work, a copy of the title work will be provided to the Surveyor. A copy of the list of impacted parcels, along with the title work, and a marked/highlighted tax map will then be sent or made available to the Design Engineer and the Project Manager. Occasionally, with the consensus of Real Estate Staff, Design, and Surveys, a preliminary interview of the property owner may be needed to verify the property ownership information of record.

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4.6.2.3 Develop Scope & Budget

Once the parent parcels are identified, a meeting between the Project Manager, MDOT Surveyor, and Real Estate Staff, must occur to scope each survey by parcel and develop an estimate of hours for each parcel. This meeting can be concurrent with determining the affected parent parcel. When developing the scope and timeline, the team will determine the extent of each survey considering cost and impact to schedule. Refer to the section titled “Field Survey of Parent Parcel(s),” for recommendations on extent of survey.

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4.6.2.4 Field Survey of Parent Parcels

It is recommended that the Surveyor contact all the affected property owners prior to entering the property(s). This contact may be accomplished via mailed letter, door hanger or personal conversation with the property owner describing the reason for the entry.

Any additional property owner information that becomes available through interactions with the property owner will be provided by the Real Estate staff or the MDOT Survey Project Manager or Region Surveyor. If the Surveyor is denied access to private property(s) they should report it immediately to the MDOT Survey Project Manager/Region Surveyor, Real Estate Staff and the Project Manager for resolution with the Michigan Attorney General. Considering the extent of the survey as determined at the scope and budget meeting, the parent parcel(s) will be surveyed with a focus on those parcel boundaries immediately impacted by the proposed acquisition. While the primary intent is to survey the additional R.O.W. that MDOT requires for the project and the parent parcel boundaries immediately impacted, efforts to provide a complete survey of the parent parcel inclusive of a remainder description and a description of the acquisition should be undertaken when practical, considering the following:

  • Impact of the acquisition to the parcel description
  • Parcel size
  • Cost and time
  • Quality of existing parent parcel description

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4.6.2.5 Submit Final Boundary Survey of Parent Parcels

After completion of field work and determination of the location of the parent parcel’s boundaries, a composite drawing showing all the parent parcels affected by the proposed R.O.W. is to be submitted to design. The use of ProjectWise is highly recommended for this transmittal. Requirements for parent parcel boundary drawing:

  • .dgn format in a file named “XXXXXX_Parcel_20YY-MM-DD.dgn”
  • Relative to project datum
  • Compliant with the current workspace used with the project - MDOT Workspace
  • Name and contact information of Surveyor within the .dgn
  • Table of corners that abut the new R.O.W. with State Plane Coordinates

The intent is that the parent parcel boundary drawing can be referenced into the design plans to enable the designer to make adjustments to the R.O.W. taking locations. Upon the submittal of the parent parcel drawing to the Designer Engineer, MDOT Survey Project Manager/Region Surveyor, Real Estate staff and the Project Manager must also be notified.

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4.6.2.6 Finalize New R.O.W. Location

Upon receipt of the parent parcel boundary drawing, the Designer will reference the drawing into the design plans. These boundary locations will void and supersede any previously calculated “non-legal” boundary locations in the model. The Designer will adjust R.O.W. takes to coincide with the final locations of the parent parcel boundary lines as depicted in the parent parcel boundary drawing. The Designer will substantially finalize the proposed R.O.W. location with input from Real Estate Staff and the Project Manager. The Real Estate Technician would then plot the parcels that involve non-permanent R.O.W. (example: temporary grading easements) and establish parcel numbering for the project.

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4.6.2.7 Draft Certificates of Survey for Review

Once the final proposed R.O.W. has been determined by the Designer, the Designer must notify the Surveyor of the location of the files in ProjectWise representing the finalized R.O.W. locations. The Surveyor will utilize the Designer’s finalized R.O.W. location to prepare individual Certified Survey drawings depicting the take and remainder parcel. The Surveyor will also prepare the take and remainder descriptions. Refer to 4.6.3 Requirements for the requirements for the survey drawing and description.

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4.6.2.8 Submit Certificate of Survey

When the Surveyor has completed each Certified Survey he/she will review each certificate to ensure it meets the PA 132 presentation requirements using the Surveyor/Real Estate Act 132 Certified Survey Requirements & Review Checklist. The Surveyor only fills out the Surveyor’s portion of the Checklist. Each survey certificate will have its own checklist The Surveyor will then submit the certificates along with the checklists to Real Estate. ProjectWise will be used for the submission to Real Estate. The Project Manager must be informed of the drawing(s) submittal.

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4.6.2.9 MDOT Review

Real Estate will examine the Certified Surveys to make sure the surveys reflect the intent of the R.O.W. calls as shown on the final R.O.W. plans and contain enough information to commence the valuation and acquisition of the needed permanent R.O.W. Real Estate will then notify the Surveyor regarding the acceptability of the Certified Surveys. If the survey(s) are found unacceptable Real Estate will notify the Surveyor and the process described in Section 4.6.2.8 Submit Certificate of Survey will be repeated.

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4.6.2.10 Return/Re-scope (if necessary)

If the Real Estate Specialist/Manager/Technician finds the Certified Survey is unacceptable or not reflective of the intent of the acquisition, the survey should be returned for revisions. If this determination arises out of changes to the scope of the project it may be necessary to re-scope the Certified Survey work. The Region Surveyor or MDOT Survey consultant Project Manager must be notified in order that a contract modification can be made. Depending on the severity of the changes, a meeting similar to the initial scope meeting may be held. For procedural steps to respond to changes please refer to Section 4.6.2.11 Change to Design Occur.

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4.6.2.11 Change to Design Occur

During the design process, there could be several unforeseen circumstances that could change the proposed R.O.W. line(s) location before the Certified Survey can be accepted by the Real Estate Staff or the Consultant Survey Project Manager before the permanent R.O.W. is acquired and the Certified Survey can be recorded in the respective County Register of Deeds Office. Items that could change the location of proposed R.O.W. line(s) may include:

  • Design change – modification to the final R.O.W. plan submittal. Initiated by Design PM or Real Estate
  • Condemnation process
  • Environmental concern
  • Historical concern
  • Archeological concern

If it is determined that the proposed R.O.W. line(s) has to be changed due any of the above mentioned circumstances, the Design PM will process the final R.O.W. revision(s) as outlined in the Road Design Manual. See Chapter 5, Section 5.21 (related Design Form 271A). After final R.O.W. revision(s) have been incorporated in the design construction plans, Real Estate will provide F.R.O.W. revision(s) documentation to the Surveyor. The Surveyor will incorporate the F.R.O.W. revision(s) into the Certified Survey(s). The ACT 132 Survey(s) will then go through the Certified Survey QA/QC review process outlined in (Section 4.6.2.9_MDOT_Review) for acceptability.

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4.6.2.12 Finalize Certified Survey

After notification from Region Real Estate that the Certified Survey is acceptable, the Surveyor will make any necessary revisions or modifications. The drawing and description will be prepared and sealed for recording (for recording process, see Section 4.6.2.14_Recordation_of_Certificate_of_Survey_by_MDOT_Real_Estate). Original hard copies and the final checklist must be transmitted to Real Estate at this time.

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4.6.2.13 Monumentation

The Surveyor will place all monuments for the survey along the proposed R.O.W. at the time of finalization of the Certified Survey described in Section 4.6.2.12 Finalize Certified Survey.

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4.6.2.14 Recordation of Certificate of Survey by MDOT Real Estate

The recording of the conveyance instruments and Certified Surveys will be completed by Real Estate Staff after the instruments are executed or upon filing of a Declaration of Taking with a court of proper jurisdiction. The ACT 132 Surveys will be incorporated and become exhibits to the actual conveyance instruments whether they are deeds, easements, or declarations of taking. These instruments may also be recorded in a separate repository in the Register of Deeds Offices reserved for ACT 132 Surveys, if available.

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4.6.2.15 Archival of Data

Upon receipt of the recorded Certificate of Survey the Real Estate Technician will provide an e-mail with a subject line of “Certified Surveys JNXXXXXX CSXXXXX” with ProjectWise links to the following address: MDOT-Survey_Support@michigan.gov The following ProjectWise links should be included:

  • Location of individual survey files in .dgn format
  • Scanned .pdf of recorded Certified Survey

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4.6.3 Requirements

4.6.3.1 Certified Survey Drawing Requirements

The requirements for the survey drawing are listed in the Surveyor/Real Estate Act 132 Certified Survey Requirements & Review Checklist.

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4.6.3.2 Certified Survey Description & Notes Requirements

The requirements for the description are listed in the Surveyor/Real Estate Act 132 Certified Survey Requirements & Review Checklist.

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4.6.4 Frequently Asked Questions

Reserved

4.7 Photogrammetric Control Surveys

4.7.1 Purpose

Photogrammetry is often used to collect data for the design of roadways. Photogrammetric surveys can be divided into two broad categories: ground control to support the photogrammetric mapping process and the actual process of collecting data using photogrammetric instruments and techniques. The concept of photogrammetric control surveys is described in Part IX.

While it is technically feasible, and very cost effective, to perform photogrammetric surveys without the presence of ground control, this practice should not be employed without the approval of the Design Survey manager. Ground control provides quality control and assurance within the photogrammetric process and this redundancy is critical in the successful completion of a photogrammetric survey.

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4.7.2 Process

Reserved

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4.7.3 Requirements

Reserved

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4.8 Frequently Asked Questions

Reserved

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