SCOTT WILSON INDIA PVT LTD

ROMDAS TRAINING

ROMDAS SURVEYSROMDAS CAN COLLECT DATA ON

• ROUGHNESS• LRP/KEY CODE RATING• INVENTORY AND CONDITION RATING• TRANSVERSE PROFILE LOGGER/RUT DEPTHS• VIDEO LOGGING ( ROW AND PAVEMENT VIEW )• GPS

SCHEMATIC DIAGRAM

ROMDAS SYSTEM COMPONENTS

NOTE FROM COMPUTER :• INTEL BASED IBM COMPATIBLE

COMPUTER.• PCMCIA SERIAL CARD TO PROVIDE

ADDITIONAL PORTS.

HARDWARE INTERFACE :• IT CONNECTS THE SPEED/DISTANCE

TRANCEDUCER AND ROUGHNESS METER TO THE COMPUTER.

SPEED/DISTANCE CENSOR :

BUMP INTEGRATOR :• FOR ROUGHNESS SURVEYS.• ATTACHED TO REAR AXLE.

ROMDAS SYSTEM COMPONENTS (Cont .)

TRANVERSE PROFILE LOGGER :• TO RECORD THE SHAPE OF THE

TRANSVERSE PROFILE. THE DATA IS PROCESSED TO CALCULATE RVT DEPTH.

VIDEO LOGGING :• TO CREATE A VIDEO RECORD OF

THE ROAD. THAT IS RIGHT-OF-WAY.• MOUNTED ON THE ROOF OF

VEHICLE.

GPS• TO CREATE A 3-DIMENTIONAL

REPRESENTATION OF ROAD ALIGNMENT

• ROAD CENTER LINE SURVEY.

VIDEO LOGGING

ROMDAS SYSTEM COMPONENTS (Cont.)

TYPE OF VEHICLE :• ALTHOUGH NOT A

COMPONENT OF ROMDAS, A VEHICLE IS REQUIRED AS A PLATFORM FOR THE INSTRUMENTS

.

CONDUCTING SURVEYS

ROAD DEFINITIONS :• ESTABLISHING THE ROADS TO BE

SURVEYED AND THE ORDER OF SURVEYS.

• EACH ROAD SHOULD BE GIVEN A ROAD ID ASSOCIATED WITH THIS WILL BE FILENAME FOR EXAMPLE IF THE ROAD ID IS SH 30 THE ROUGHNESS FILE MAY BE CALLED RD SH30.

• ALL THE ABOVE DATA SHOULD BE DEFINED BEFORE START OF SURVEY AND ENTERED INTO ROMDAS ROAD DEFINITIONS DATA BASE.

GPS SURVEYS

• AUTOMATED PROCESS WHEREIN ROMDAS MONITORS AND STORES THE OUTPUT FROM THE GPS RECEIVER.

• IF PDOP IS LOW – WHICH MEANS THAT THERE ARE INSUFFICIENT SATTELITES FOR A GOOD FIX A WARNING WILL BE GIVEN BY ROMDAS. THE SURVEY CAN CONTINUE AND PDOP VALUE WILL BE IN THE FILE, SO THERE PERIODS CAN BE

IDENTIFIED LATER.

LOCATION REFERENCING POINTS

• THE FIRST FIELD TASK OF EVERY PROJECT SHOULD BE TO CONDUCT A LOCATION REFERENCE POINT (LPR) SURVEY.

• LINEAR REFERENCING SYSTEM TO BE ADOPTED, THAT IS THE SURVEY WILL START AT A GIVEN POINT AND PROGRESS ALONG THE ROAD. THUS THE SURVEY CHAINAGE INCREASES MOVING AWAY FROM THE START POINT.

• TO MINIMISE ERRORS SELECT L RPs AT REGULAR INTERVALS GENERALLY 1 KM

• .

•RESET THE CHAINAGE TO ZERO AT EACH LRP THEREBY EXPRESSING DATA IN TERMS OF THE OFFSET FROM THE LAST LRP, FOR EXAMPLE 32 + 150.• THE LRP MAY BE A KM POST, A BRIDGE OR ANY PERMANENT FEATURE ALONG THE ROAD.• DIGITAL PHOTOGRAPHS SHOULD ALWAYS BE TAKEN OF LRPs TO PROVIDE A PERMANENT RECORD, THIS IS PARTICULARLY TRUE OF START AND END POINTS

• . 0 1 20.9 km 1.0 km

0.4 km

R R

0.5 km

km point: 1.3

km post: 1.4

ref post: 1 + 0.4

ref post: 2 - 0.6

ref point: RR239 + 0.8

Addresses

Location

RR239

KEY CODE EVENTS

. TO ESTABLISH CHAINAGE OF THE ROADSIDE EVENTS/INVENTORY LIKE ‘abadi’ , INTERSECTION AND CD STRUCTURES

•

ROUGHNESS MEASUREMENT

• ROUGHNESS – REFERS TO REGULARITY OF SURFACE FINISH IN LONGITUDINAL AND TRANSVERSE DIRECTIONS. STANDARDS AND TOLERANCE OF SURFACE EVENNESS ARE PRESCANNED IN IRC-SP-16-2004

• SURFACE EVENNESS AFFECTS VEHICLE SPEED, COMFORT, VEHICLE OPERATING COST AND SAFETY

Measure of vertical profile inRoughness Calibration each wheelpath in (m/km)

BUMP INTEGRATOR

• FITTED WITH THE REAR AXLE• DIFFERENTIAL MOVEMENT BETWEEN THE

REAR AXLE AND THE BODY OF VEHICLE DUE TO ROAD UNEVENNESS IS MEASURED BY THE UPWARD VERTICAL MOVEMENT OF A WIRE WHICH IS TRANSMITTED INTO UNIDIRECTIONAL ROTARY MOVEMENT OF THE PULLEY OF THE INTEGRATOR UNIT. THE ROTATIONAL MOVEMENT OF THE PULLEY IS CONVERTED INTO ELECTRICAL PULSES WHICH IS RECORDED BY THE COUNTERS

• ROAD ROUGHNESS IS AFFECTED BY VEHICLE SPEED . A BUMP GETS MAGNIFIED IF THE VEHICLE SPEED IS NOT MAINTATINED. VEHICLE LOAD IS ANOTHER FACTOR WHICH INFLUENCES ROUGHNESS MEASUREMENT

• IT SHOULD BE ENSURED THAT THE OUTER VEHICLE WHEEL TRAVELS ON THE WHEEL PATH

ROUGHNESS SURVEYS

• TO BE DONE BY DRIVING THE VEHICLE AT A CONSTANT SPEED.

• IF NECESSARY TO OPERATE AT A RANGE OF SPEEDS DIFFERENT CALIBRATION EQUATIONS SHOULD BE ESTABLISHED TO COVER THIS RANGE. THE ROMDAS SOFTWARE WILL APPLY THE APPROPRIATE EQUATIONS GIVEN THE SURVEY SPEED.

• THE VEHICLE SHOULD ALSO BE RECALIBERATED AT 5 – 10000 KM.

VIDEO SURVEYS

• TO BE DONE IN CONJUNCTION WITH ROUGHNESS SURVEYS.

• ENSURE SUFFICIENT HARD DISK SPACE.

• ALWAYS START THE RECORDING BEFORE THE SURVEY STARTS AND END IT AFTER THE SURVEY IS COMPLETED

• .

TRANSVERSE PROFILE LOGGER (TPL)

• TO BE DONE IN

CONJUNCTION WITH ROUGHNESS SURVEYS.

• BEFORE START OF SURVEY TEST FIRE ALL THE SENSORS.

• THE SAMPLING INTERVAL OF THE TPL IS A FUNCTION OF

SPEED FOR INTERVALS OF 10M, 80 KM/HR IS THE RECOMMENDED SPEED.

LASER SURVEYOR SURVEY

TO ADEQUATELY POSITION ROADSIDE EVENTS SUCH AS LRPs

THIS DATA IS RECONCILED WITH THE GPS TO ESTABLISH ITS ACCURATE POSITION

.

CALIBRATION

• TO ENSURE REPEATABILITY AND REPRODUCIBILITY OF MEASUREMENT BY THE MACHINE. INITIAL STANDARDISATION AND SUBSEQUENT RECALIBRATION ARE ESSENTIAL.

• THE MEASUREMENT OBTAINED FROM THE RESPONSE TYPE DEVISES MUST BE CORRECT TO THE STANDARD ROUGHNESS SCALE.

• MERLIN ( MACHINE FOR EVALUATING ROAD ROUGHNESS USING LOW COST INSTRUMENT) . USED AS A STANDARD ROUGHNESS SCALE.

PROCEDURE• NUMBER OF TEST SITES, EACH OF 300 M TO 400 M

LENGTH CHOSEN TO REPRESENT A WIDE RANGE OF SPECTRUM OF ROUGHNESS RANGING FROM VERY SMOOTH TO VERY ROUGH ARE SELECTED.

• THE ENTIRE LENGTH OF ALL SELECTED SITES SHOULD HAVE UNIFORM ROUGHNESS AND FREE OF SURFACE DEFECTS.

• WHEEL PATHS ARE MARKED, AS ALSO START AND END POINTS.

• MERLIN IS RUN ON THE WHEEL PATHS, BOTH IN UP AND DOWN DIRECTIONS. AVERAGE VALUE IS TAKEN AS THE REPRESENTATIVE ROUGHNESS VALUE OF SECTION.

• ROMDAS IS RUN IN THE WHEEL PATH AT DIFFERENT SPEEDS, FOR EACH SPEED THREE RUNS ARE MADE.

• BASED ON THESE TWO SETS OF OBSERVATIONS ONE WITH ROMDAS AND ONE WITH MERLIN, A CORRELATION IS ESTIMATED. FROM THESE CORRELATIONS THESE CORRECTED ROUGHNESS VALUES ARE OBTAINED.

DISTANCE METER CALIBRATION

• THE DISTAN CE METER CALIBERATION IS DONE BY ACCURACY MEASURING A DISTANCE OF AT LEAST 300 M ON A FLAT, STRAIGHT SECTION OF ROAD WITH A LITTLE TRAFFIC.