The document discusses weigh-in-motion (WIM) technology, its types, sensors, and data acquisition methods, highlighting its significance in managing vehicle overloading and improving road safety. It details various WIM systems such as low-speed and high-speed installations, along with their advantages and limitations. The effectiveness and implementation of WIM systems in traffic management, including case studies from various countries, are also examined, emphasizing their role in reducing road deterioration and enhancing traffic data collection.

1. Presented by,
VIJAI KRISHNAN V
M.Tech Student
Transportation Engg.
Guided by,
Dr. BINO I KOSHY
Professor
Dept. of Civil Engineering
RIT, Kottayam

2. Contents
 Introduction
 Weigh-in-Motion Technology
 Types of WIM Systems
 Sensors
 Data Acquisition & Storage
 Implementation
 Case Studies
 Uses & Limitations
 WIM Systems in India
 Conclusion
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3. Introduction
 Overloading of vehicle
 Damage & degradation of road infrastructure
 Higher accident risks
 Affect road traffic
 Affect truck stability, maneuverability etc.
 Pollution, noise, vibration & fuel consumption
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4.  Static Weighing Systems
 Accurate
 Rarely used for enforcement
 Limitations
 Trucks are stopped
 Congestion
 Reduce efficiency of freight
transport
 Require large area
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Static weigh bridge

5.  Control overloaded vehicle without disrupting
traffic & freight operations
 Legally loaded vehicles are passed
 Offended vehicles are separated from traffic
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Weigh-in-Motion Technology
Process of determining any one or more of the
parameters such as the vehicle mass, axle load, wheel
load or other parameters of a moving vehicle, when
it crosses over a set of sensors

6. Types of WIM Systems
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Permanent
Systems
Portable
Systems
LS-WIM
HS-WIM
B-WIM
P-WIM
WIM
Speed
Installation
location

7. 1. Low-Speed WIM system
(LS-WIM)
 Optimal speed 5 to 10km/h
 Minimum accuracy of 95%
 Outside main traffic flow
2. High-Speed WIM system
(HS-WIM)
 Weighs at desired speed
upto 130km/h
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LS-WIM
HS-WIM
(Jacob B. & Beaumelle V., 2010)

8. 3. Pavement-based WIM
systems (P-WIM)
 Sensors installed on
road surface
 Limitations:
 Traffic interruption
 Poor durability
 Accuracy is less on
rough road
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P-WIM installation on pavement

9. 4. Bridge-based WIM system (B-WIM)
 Measure deformation of bridge
 Strain sensors installed on bridge soffit
 Advantages over P-WIM
 No traffic interruption for installation
 Bridge health monitoring & assessment
 Non-destructive implementation
 More durable
 Multiple heavy vehicles simultaneously on bridge, result
in biased data
 SiWIM – a commercial B-WIM system
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10. 5. Portable WIM systems
 Sensors affixed to pavement surface by tapes
 2 sensors at 2.5 m distance
 Advantages:
 Convenient & cost effective
 No traffic closure or trench required
 Limitations:
 Require in-situ calibration at each site
 Loss accuracy & sensitivity over time
 Recommended for 7 days only
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11. 29-May-18 Weigh-in-Motion Systems 11
Installing
Portable WIM
system on
pavement
Portable WIM
data
(Faruk et al.,
2016)

12. Sensors
 Measure axle load & spacing
 Convert load to electric signals
1. Based on width of sensor
1. Plate Sensors
2. Strip Sensors
2. Based on purpose
1. Weighing sensors
2. Axle detecting sensors
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13. 1. Plate sensors
 Use strain gauges
 High strength, rectangular steel plates
 More accurate, but costly
 Difficult to install
2. Strip Sensors
 Width is only few centimetres
 Less expensive & easy to install
 Highly accurate on smooth road surface, but less
accurate on deteriorated surfaces
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14. 29-May-18 Weigh-in-Motion Systems 14
Strip Sensor
(http://www.mdpi.com)
Bending Plate Sensor

15. 3. Weighing Sensors
 Vehicle load  Electric Signal
 Types of weighing sensors
1. Foil Strain Gauges
 Most commonly used
 Cheap & have acceptable accuracy
 Not suitable for long term
2. Vibrating Wire Strain Gauge
 Good durability & require less surface preparation
3. Fibre Optic Sensors
 Not affected by electromagnetic interference
 Cheap, small in size & more durable
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16. 4. Axle Detectors
 Traditional axle detectors
 Pneumatic tubes & induction loops
 Require lane closure
 2 parallel detectors at known spacing
 Sharp response when vehicle wheel pass over the detectors
 Free-of-Axle (FAD) Detectors
 No need of lane closure
 FAD sensor measure strain response
 Image processing & video-based systems
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17.  Installation Location of B-WIM sensors
 Function of sensor
 Weighing sensor  At near mid-span of bridge
 Axle detectors  Traditional sensors on road surface & FAD
sensors under the bridge
 Type of Bridge
 T-Beam RCC Bridge  FAD sensors oriented longitudinally &
installed close to beginning or end of bridge span, directly
below wheel path
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18. 29-May-18 Weigh-in-Motion Systems 18
Bridge-based WIM system
(https://www.cestel.eu)
Weighing
Sensors
Axle
Sensors

19. Data Acquisition & Storage
 Sensors & cameras are communicated with on-site
data acquisition system (WIM data cabinet)
 Wired or wireless connection
 Data transmitted to control centre server
 WIM software displays:-
 Number of axles
 Axle weight
 Axle spacing
 Vehicle speed
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 Vehicle class
 Gross Vehicle Weight
 Date & time of passing
 Overload warning

20.  Event-triggering mechanism to reduce storage space
 Record events equal to or exceeding the lower limit
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WIM Data Cabinet (FHWA, 2009) Controller Unit

21. 29-May-18 Weigh-in-Motion Systems 21
WIM
Sensors
Signal
Amplification
Data acquisition
unit
Server at
control centre

22. 29-May-18 Weigh-in-Motion Systems 22
WIM software showing weight violation list (http://www.its-is.com.my)

23. Implementation
 Details to be considered :-
 Average daily heavy vehicle traffic
 Structure of heavy vehicle
 Number of overloaded vehicles
 Source & destination of heavy vehicles
 Type & condition of road
 Horizontal & vertical alignment of road
 Geometric road location
 Pilot implementation is done first as WIM is costly
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24.  Effectiveness is then measured based on:
 Change of vehicle travel time
 Traffic in central areas of the city
 Change in distance covered
 Change in impact on environment
 New traffic conditions (change in time lost, queue
length, number of stops etc...)
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25. Case Studies
1. City of Gdynia, Poland
 To reduce heavy & overloaded vehicles from Port of
Gdynia entering into city central areas
 Measurement done at urban entry points
 Significant reduction in heavy vehicle on access roads
to city & no heavy vehicle traffic on entries into city
centre
 Shifting to smaller vehicle
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26. 2. Netherlands & France
 WIM + video surveillance or license plate number
recognition cameras (ANPR)
 Companies classified by severity level
3. USA
 To assess road infrastructure damage & impose weight
enforcement
 Portable WIM units deployed in Texas to collect traffic
details
4. Taiwan
 HS-WIM system for direct enforcement in 1998 & 2010
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27. Uses of WIM
 Reduce overloaded vehicles
 Control access to busy parts of city
 Reduce road deterioration & repairs
 Road safety
 Bridge assessment
 Minimize environmental impacts
 Economical benefit
 Road infrastructure planning, design & maintenance
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28. Limitations
 Accuracy of sensor decrease over time
 Malfunctioning of sensors affect data quality
 More time & cost for calibration & installation
 Lifetime of P-WIM is short
 Increase risk & traffic on secondary roads
 Laws & legislations
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29. WIM Systems in India
 Overloaded vehicle – 13% of total accidents claiming
about 22,000 lives
 NHAI Recommendations
 Locations – entries to highways, toll plazas & locations
where heavy loads are likely to be carried (industries)
 Camera – to capture image of offending vehicle & its
registration number
 Alert messages via mobile apps to enforcement or
highway patrol agencies
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30.  Accuracy – 98%
 Minimum axle weight of 40 tonnes at speed  5km/h
 Should work satisfactorily under:
 Wet road conditions
 Temperature range of -20C to +55C
 Relative humidity upto 95%
 Standby battery
 System shall be duly calibrated, tested & approved
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31.  Supreme Court ordered to check & divert overloaded
vehicles entering Delhi to reduce pollution
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32. Conclusion
 Effective in overweight enforcement
 Optimize life expectancy of road & bridges
 Increase mobility & safety
 Collect traffic & vehicle weight data
 Costly & sophisticated but accurate & efficient
 Assist in planning, design & management
 In-depth analysis is necessary since a hasty change
may deteriorate the traffic
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33. References
1. Oskarbski, J., and Kaszubowski, D., Implementation of Weigh-in-Motion
system in freight traffic management in urban areas, 2nd International
Conference “Green Cities – Green Logistics for Greener Cities”, Poland,
Transportation Research Procedia,Vol: 16, 2016, 449-463.
2. Haugen, T., Levy, J. R., Aarke, E., and Tello, M. E. P., Weigh-in-Motion
equipment – experiences and challenges, 6th Transport Research Arena,
Transportation Research Procedia, Vol: 14, 2016, 1423-1432.
3. Faruk, A. N.M., Liu, W., Lee, S. I., Naik, B., Chen, D. H. and Walubita, L. F.,
Traffic volume and load data measurement using portable weigh in motion
system: A case study, International Journal of Pavement Research and
Technology, Vol: 9, 2016, 202-213.
4. Jacob, B. and Cottineau, L. M., Weigh-in-motion for direct enforcement of
overloaded commercial vehicles, 6th Transport Research Arena,
Transportation Research Procedia, Vol: 14, 2016, 1413-1422.
5. Jacob, B., and Beaumelle, V. F. L., Improving truck safety: Potential of weigh-
in-motion technology, IATSS Research, Vol: 34, 2010, 9-15.
6. Yu, Y., Cai, C.S., and Deng, L., State-of-the-art review on bridge weigh-in-
motion technology, Advances in Structural Engineering, 2016, 1-17.
7. Burnos, P. and Gajda, J., Vehicle’s Weigh-in-Motion system for enforcement
in Poland, 11th ITS European Congress, Glasgow, Scotland, 2016, 1-11.
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34. 8. Karim, M. R., Ibrahim, N. I., Saifizul, A. A. and Yamanaka, H., Effectiveness
of vehicle weight enforcement in a developing country using weigh-in-
motion sorting system considering vehicle by-pass and enforcement
capability, IATSS Research, Vol: 37, 2014, 124-129.
9. Stanczyk, D. and Klein, E., Heavy traffic data collection and detection of
overloaded HGV, Transport Research Arena – Europe, Procedia – Social and
Behavioral Sciences, Vol: 48, 2012, 133-143.
10. Lydon, M., Taylor, S. E., Robinson D., Mufti A., and Brien E. J. O., Recent
developments in bridge weigh in motion (B-WIM), Journal of Civil Structural
Health Monitoring, Vol: 6, No: 1,2016, 69-81.
11. Batenko, A., Grakovski, A., Kabashkin, I., Petersons, E. and Sikerzhicki, Y.,
Weight-in-motion (WIM) measurements by fiber optic sensor: Problems and
solutions, Transport and Telecommunication, Vol: 12, No: 4, 2011, 27-33.
12. NHAI, Advanced Traffic Management System (ATMS) on NHs – Functional
and Technical Specifications, Highway Automation and Management
Division, 2016, 60-62.
13. FHWA, LTBP Program’s Literature Review on Weigh-in-Motion Systems, US
Department of Transportation, 2016.
14. FHWA, Deploying Weigh-In-Motion Installations on Asphalt Concrete
Pavements, US Department of Transportation, 2008.
15. EPCA for Delhi, Installation of weigh-in-motion bridges at all entry points,
MoRTH, 2016.
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