LSIT Plan and Map Reading 3 — Questions and Answers
Question 1: On a subdivision plat, what does 'L=125.43' typically refer to when associated with a curved boundary?
- The chord length of the curve
- The arc length of the curve (Correct answer)
- The radius of the curve
- The tangent length from the PC
Correct answer: The arc length of the curve
The label 'L=' on a curved boundary denotes the arc length along the curve between the two endpoints.
Question 2: Which map projection is commonly used for state plane coordinate systems in US surveys?
- Mercator and Lambert Conformal Conic only
- Transverse Mercator and Lambert Conformal Conic (Correct answer)
- Albers Equal-Area and Azimuthal Equidistant
- Gnomonic and Stereographic
Correct answer: Transverse Mercator and Lambert Conformal Conic
US State Plane Coordinate Systems use either Transverse Mercator (for north-south zones) or Lambert Conformal Conic (for east-west zones).
Question 3: A 'Point of Curvature' (PC) on a highway plan marks which location?
- The center of a horizontal curve
- Where a tangent transitions into a horizontal curve (Correct answer)
- The highest point on a vertical curve
- Where two curves of equal radius meet
Correct answer: Where a tangent transitions into a horizontal curve
The PC is the point where a straight tangent section ends and a circular horizontal curve begins.
Question 4: On a survey map legend, a symbol showing a filled circle at a corner followed by a pipe description typically represents what?
- A water well location
- A found or set iron pipe or monument (Correct answer)
- A utility manhole
- A traffic signal pole
Correct answer: A found or set iron pipe or monument
Filled circles or squares with pipe/rod descriptions in a legend denote survey monuments, either found during fieldwork or set by the surveyor.
Question 5: What information does the 'basis of bearings' note on a survey plan provide?
- The magnetic declination at the time of survey
- The reference direction from which all bearings on the map are derived (Correct answer)
- The grid convergence angle for the state plane system
- The azimuth of the sun at noon on the survey date
Correct answer: The reference direction from which all bearings on the map are derived
The basis of bearings statement identifies the reference line and its direction used to establish all other bearings shown on the survey.
Question 6: On a grading plan, a spot elevation shown inside a triangle symbol typically indicates what?
- An existing ground elevation
- A finished grade or proposed elevation (Correct answer)
- A benchmark elevation
- A cut depth at that location
Correct answer: A finished grade or proposed elevation
Triangular symbols with elevations on grading plans conventionally denote proposed or finished grade elevations.
Question 7: A 'section corner' monument shown on a PLSS-based survey plat represents what?
- The corner of a private lot within a subdivision
- The corner of a one-mile-square section established by the US Public Land Survey System (Correct answer)
- A corner shared between two states
- The center point of a township
Correct answer: The corner of a one-mile-square section established by the US Public Land Survey System
Section corners are the controlling monuments established by the USPLSS that define the one-mile-square sections of the survey grid.
LSIT Plan and Map Reading 3
On a subdivision plat, what does 'L=125.43' typically refer to when associated with a curved boundary?