ITEM 1: INTRODUCTION

SELECTING THE LOCATION

OF A PROPOSED

HIGHWAY IS AN

IMPORTANT INITIAL

STEP IN ITS DESIGN.

THE DECISION TO

SELECT A PARTICULAR

LOCATION IS USUALLY

BASED ON

TOPOGRAPHY, SOIL

CHARACTERISTICS, ENVIRONMENTAL FACTORS SUCH AS

NOISE AND AIR POLLUTION, AND ECONOMIC FACTORS.

THE DATA REQUIRED FOR THE DECISION PROCESS ARE

USUALLY OBTAINED

FROM DIFFERENT

TYPES OF SURVEYS,

DEPENDING ON THE

FACTORS BEING

CONSIDERED. MOST

ENGINEERING

CONSULTANTS AND

STATE AGENCIES PRESENTLY INVOLVED IN HIGHWAY

LOCATIONS USE COMPUTERIZED TECHNIQUES TO

PROCESS THE VAST AMOUNTS OF DATA THAT ARE

GENERALLY HANDLED IN THE DECISION PROCESS. THESE

TECHNIQUES INCLUDE REMOTE SENSING, WHICH USES

AERIAL PHOTGRAPHS FOR THE PREPARATION OF MAPS,

AND COMUTER GRAPHICS, A COMPUTER MONITOR. IN

THIS REPORT, WE PRESENT A BRIEF DESCRIPTION OF THE

CURRENT TECHNIQUES USED IN HIGHWAY SURVEYS TO

COLLECT AND ANALYZE THE REQUIRED DATA, AND THE

STEPS INVOLVED IN THE PROCEDURE FOR LOCATING

HIGHWAYS. WE ALSO COVER EARTHWORK

COMPUTATIONS AND MASS DIGRAMS, SINCE AN

ESTIMATE OF THE AMOUNT OF THE EARTHWORK

ASSOCIATED WITH ANY GIVEN LOCATION IS REQUIRED

FOR ECONOMIC EVALUATION OF THE HIGHWAY AT THAT

LOCATION. THE RESULT OF THE ECONOMIC EVALUATION

AIDS IN THE DECISION TO ACCEPT OR REJECT THAT

LOCATION.

ITEM 2: HIGHWAY SURVEY METHODS

HIGHWAY SURVEYS USUALLY

INVOLVE MEASURING AND

COMPUTING HORIZONTAL

AND VERTICAL ANGLES,

VERTICAL HEIGHTS

(ELEVATIONS) AND

HORIZONTAL DISTANCES.

ITEM 3: GROUND SURVEYS

GROUND SURVEYS ARE THE BASIC LOCATION

TECHNIQUES FOR

HIGHWAYS. THE TOTAL

STATION IS USED OF

MEASURING ANGLES IN

BOTH VERTICAL AND

HORIZONTAL PLANES,

DISTANCES AND CHANGES

IN ELEVATION.

ITEM 5: TOTAL STATION

A TOTAL STATION IS BOTH AN ELECTRI-THEODOLITE AND

ELECTRONIC DISTANCE-MEASURING DEVICE (EDM).

ITEM 5a: ELECTRIC DISTANCE MEASURING DEVICES (EDM)

AN EDM DEVICE CONSISCTS MAINLY OF A TRANSMITTER

LOCATED AT ONE END OF THE

DISCANCE TO BE MEASURED AND A

REFLECTOR AT THE OTHER END. IT IS

DETERMINES THE DISTANCES UP TO

1,000 METERS IN AVERAGE

ATMOSPHERIC CONDITIONS.

ITEM 6: MEASUREMENT OF HORIZONTAL ANGLES

A HORIZONTAL ANGLE CAN BE

MEASURED BY SETTING THE

THEODOLITE OR TOTAL STATION

DIRECTLY OVER THE POINT O. WHEN

USING A TOTAL STATION, THE ANGLE

MEASURED IS SHOWN IN A DIGITAL

READOUT WHEN A HORIZONTAL READ OUT IS SELECTED.

ITEM 7: MEASUREMENT OF VERTICAL ANGLES

THE THEODOLITE MEASURES VERTICAL ANDLES BY USING

THE FIXED VERTICAL GRADUATED ARC OR VERNIER AND

A SPIRIT LEVEL ATTACHED TO THE TELESCOPE. WHEN

USING TOTAL STATION, THE ANGLE

MEASURED IS SHOWN IN A DIGITAL

READOUT WHEN A VERTICAL

READOUT IS SELECTED.

ITEM 8: DUMPTY LEVEL

THE ESSENTIAL PARTS OF A

LEVEL ARE THE TELESCOPE WITH

VERTICAL AND HORIZONTAL

CROSS HAIRS, A LEVEL BAR, A

SPINDLE, AND A LEVELING HEAD.

THE LEVER BAR ON WHICH THE

TELESCOPE IS MOUNTED IS RIGIDLY FIXED TO THIS

SPINDLE.

ITEM 9: SURVEY DATA COLLECTOR

SURVEY DATA COLLECTORS ARE

DEVICES THAT CONNECT TO ANY

SURVEY INSTRUMENT (TOTAL

STATION) THROUGH A CABLE OR

BLUETOOTH THAT ALLOWS A SURVEYOR TO SECURE

INSTRUMENT'S RAW DATA STRING INTO COORDINATES

AND ELEVATION.

ITEM 10: MULTILAYERED INFORMATION

WITH THE DIGITAL AGE, MANY

PROJECTS ARE SUBMITTED IN

DIGITAL FORMAT LIKE COMPUTER

AIDED DESIGN DRAFTING, OR CADD

USING PROGRAMS SUCH AS

AUTOCAD.

ITEM 11: GLOBAL POSITIONING SYSTEM SURVEYS

THE GLOBAL POSITIONING SYSTEM (GPS) IS A SATELLITE-

BASED SYSTEM THAT USES A CONSTELATION OF 28

SATELLITES TO GIVE A USER AN ACCURATE POSITION.

GPS SURVEYING IS AN EVOLVING PERFORMING TYPES OF

GPS SURVEYS RECEIVERS AND

SOFTWARE SHOULD BE SUITABLE FOR

A SPECIFIC SURVEY AS STATED BY THE

MANUFACTURER.

ITEM 12: ANTENNAS

WHENEVER FEASIBLE, ALL

ANTENNAS USED FOR A PROJECT

SHOULD BE IDENTICAL. FOR VERTICAL CONTROL

SURVEYS, IDENTICAL ANTENNAS ARE USED UNLESS

SOFTWARE IS AVAILABLE TO ACCOMODATE THE USE OF

DIFFERENT ANTENNAS. THE USE OF RANGE POLES

AND/OR STAKE-OUT POLES TO SUPPORT GPS ANTENNAS

ARE ONLY USED FOR THIRD ORDER HORIZONTAL AND

GENERAL-ORDER

.SURVEYS

ITEM 13: REMOTE SENSING

REMOTE SENSING IS THE MEASUREMENT OF DISTANCES

AND ELEVATIONS BY USING DEVICES LOCATED ABOVE

THE EARTH, SUCH AS AIRPLAINES OR ORBITTING

SATELLITES USING GLOBAL POSITIONING SATELLITE

SYSTEM (GPS).

ITEM 14: OBTAINING AND INTERPRETING AERIAL

PHOTOGRAPHS

THE PHOTOGRAPHS ARE TAKEN FROM AIRPLANES WITH

THE AXIS OF THE CAMERA AT A NEAR VERTICAL

POSITION. THE ASIX SHOULD BE EXACTLY VERTICAL BUT

THIS POSITION IS USUALLY DIFFICULT TO OBTAIN DUE TO

THE MOTION OF THE AIRCRAFT.

ITEM 15: PHOTOGRAMMETRY

PHOTOGRAMMETRY IS

THE SCIENCE OF MAKING

MEASUREMENTS FROM

PHOTOGRAPHS,

ESPECIALLY FOR

RECOVERING THE EXACT

POSITIONS OF SURFACE

POINTS. MOREOVER, IT MAY BE USED TO RECOVER THE

MOTION PATHWAYS OF DESIGNATED REFERENCE POINTS.

ITEM 16: FIDUCIAL

MARKS

A FIDUCIAL MARK IS AN

OBJECT PLACED IN THE

FIELD OF VIEW OF AN

IMAGING SYSTEM

WHICH APPEARS IN THE IMAGE PRODUCED, FOR USE AS A

POINT OF REFERENCE OR A MEASURE. IT MAY BE EITHER

SOMETHING PLACED INTO OR ON THE IMAGING SUBJECT,

OR A MARK OR SET OF MARKS IN THE RETICLE OF AN

OPTICAL INSTRUMENT.

ITEM 17: PRINCIPAL POINT

PRINCIPAL POINT IS THE POINT

OF INTERSECTION OF THE

OPTICAL AXIS OF THE AERIAL

CAMERA WITH THE

PHOTOGRAPHIC PLANE. IT IS

ALSO THE INTERSECTION OF THE

LINES JOING OPPOSITE FIDUCIAL

MARKS GIVES THE GEOMETRIC

CENTER OF THE PHOTOGRAPH.

ITEM 18: CONTROL POINTS

CONTROL POINT IS THE PRIMARY/BASE CONTROL USED

FOR PRELIMINARY MEASUREMENTS;

IT MAY CONSIST OF ANY KNOW POINT

CAPABLE OF ESTABLISHING

ACCURATE CONTROL OF DISTANCE

AND DIRECTION.

ITEM 19: AERIAL SURVEY

AERIAL SURVEY IS A METHOD

OF COLLECTING GEOMATICS

OR OTHER IMAGERY BY

USING AEROPLANES,

HELICOPTERS, UAVS,

BALLOONS AND OTHER

AERIAL METHODS.

ITEM 20: STEREOSCOPES

STEREOSCOPES IS THE INSTRUMENT THAT CONVERTS

THE AERIAL PHOTOGRAPHS INTO MAPS. IT IS ALSO A

TECHNIQUE FOR CREATING OR ENHANCING THE ILLUSION

OF DEPHT IN AN IMAGE BY

MEANS OF STEREOPSIS FOR

BINOCULAR VISION.

ITEM 21: SCHEMATIC OF A SINGLE AERIAL PHOTOGRAPH

EVEN WHEN THE AXIS OF THE CAMERA IS PERFECTLY

VERTICAL THE SCALE ON THE PHOTOGRAPH VARIES

FROM POINT TO POINT AND DEPENDS ON THE ELEVATION

OF THE POINT AT WHICH THE SCALE IS DETERMINED.

ITEM 22: LIDAR

SCANNING

LIDAR IS A REMOTE SENSING

TECHNOLOGY THAT

MEASURES DISTANCE BY

ILLUMINATIONG A TARGET WITH LASER AND ANALYZING

THE REFLECTED LIGHT.

ITEM23: AIRBORNE LIDAR

AIRBORNE LiDAR IS PERFORMED

FROM AN AIRCRAFT. THE

INSTRUMENT IS ATTACHMENT

ATTACHED TO A FIXED-WING OR

ROTARY-WINGS AIRCARFT AND

THE SCANNER EMITS A LIGHT

LASER BEAM THAT IS REFLECTED FROM A MIRROR AND

DIRECTED AT THE SURFACE OF THE EARTH.

ITEM 25: TERRESTRIAL LIDAR

THE TERRESTRIAL LiDAR SCANNER IS A SPECIFIC,

LOCALIZED FORM OF LiDAR. THE SCANNED IS MOUNTED

ON A TRIPOD OR STATIONARY VEHICLE. A LIGHT PULSE IS

TRANSMITTED AND THE TIME IT TAKES TO RETURN IS

MEASURED PROVIDING THE SOFTWARE OF A

POSITIONING ON THE EARTH.

ITEM 26: SCANNER ADVANTAGES

THE SCANNER IS MOST USEFUL WHEN CONFIDENCE IN

THE DATE IS IMPORTANT, THERE ARE TIME CONSTRAINTS

ON A PROJECT, FAST TURN-AROUND IS NEEDED, OR

WHEN THE AREA IS DIFFICULT OR DANGEROUS TO

ACCESSOR

DANGEROUS TO MEASURE.

ITEM 27: GEOGRAPHIC INFORMATION SYSTEMS

GEOGRAPHIC INFORMATION SYSTEMS (GIS) CAPTURE,

STORE, ANALYZE, AND MANAGE DATA ASSOCIATED

ATTRIBUTES WHICH ARE SPATIALLY REFERENCED TO THE

EARTH. GIS IA A COMPUTER SYSTEM ACCESSING A

DATABASE OF LAYERS OF INFORMATION.

ITEM 28: GPS

SATELLITE SURVEYING AND SATELLITE IMAGERY

SURVEYORS USE GLOBAL POSTIONING

SYSTEMS (GPS) IN ALL KINDS OF SURVEYING. SATELLITE

IMAGERY IS ALSO BEING USED TO MONITOR MOVEMENTS

ON THE EARTH'S SURFACE-EARTH QUAKE ZONES,

POTENTIAL MUD SLIDES OR EVEN TROOPS ON THE MOVE

IN A WAR ZONE.

ITEM 29:

HYDROGRAPHIC SURVEYING

HYDROGRAPHIC SURVEY IS THE SCIENCE OF

MEASUREMENT AND

DESCRIPTION OF FEATURES

WHICH AFFECT MARITIME

NAVIGATION, MARINE

CONSTRUCTION,

DREDGING, OFFSHORE OUL EXPLORATION, DRILLING AND

RELATED ACTIVITIES.

ITEM 30: SUMMARY

THE SELECTION OF A SUITABLE LOCATION FOR A NEW

HIGHWAY REQUIRES INFORMATION OBTAINED FROM

HIGHWAY SURVEYS. THESE SURVEYS CAN BE CARRIED

OUT BY EITHER CONVENTIONAL GROUND METHODS OR

USE OF ELECTRIC EQUIPMENT AND COMPUTERS. A BRIEF

DESCRIPTION OF SOME OF THE MORE COMMONLY USED

METHODS OF SURVEYS HAS BEEN PRESENTED TO

INTRODUCE THE READER TO THESE TECHNIQUES.