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Surveillance. Is necessary to manage trafficWithout surveillance, there is no knowledge of what is occurring. Surveillance. When choosing surveillance system / technologyType of data collectedCost of data collectionAccuracy of data collectedReliability of equipmentFrequency of communications
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1. Surveillance
2. Surveillance Is necessary to manage traffic
Without surveillance, there is no knowledge of what is occurring
3. Surveillance When choosing surveillance system / technology
Type of data collected
Cost of data collection
Accuracy of data collected
Reliability of equipment
Frequency of communications
Flexibility
4. Type of Data Volume
Vehicle presence
Lane occupancy
Vehicle classification
Vehicle speed / travel time
Weight
ID
Other (location? status? revenue?)
5. Cost of System Purchase
Installation
Operation
Maintenance
6. Cost Purchase price
Sensor
Electronics
Communications
Software
License? (How many can you use?)
7. Cost Installation location effects cost
In ground
Below ground
Pole mounted
Bridge mounted
Need for traffic control?
Communications
Power
Cabinets
8. Cost Operations
Power
Communications
Bandwidth required
Wireless / wireline
Frequency of communications
Staff oversight
9. Cost Maintenance
Mean time before failure (life cycle costs)
Routine maintenance requirements
External effects
Bad weather
Deteriorated pavement conditions
Replacement parts (sole source?)
Ease of sensor replacement
10. Accuracy How important is it?
Can you accept small errors?
Volume +5%
Speed + 3 mph
Error in reading Toll tags?
Classification of truck
It depends
11. Reliability What happens if a data point is missing?
Once
Frequently
Consistently but intermittently
Completely
Fail safe design
Graceful failure design
12. Reliability To get better reliability
Purchase better equipment (price / warranty)
Build redundantly
Must trade off against cost
13. Communications How often does data get transmitted from
Sensor
Location
14. Communications Frequency of communications
Each activation?
Each second
20 seconds
5 minutes
15 minutes
Hourly
Daily
15. Communications Size of data packet
Summary statistic
Raw data
For example
Digital image of picture
Analog image of picture
Count of cars made from picture
Count of cars made from 15 minutes of pictures
16. Communications Must select communications strategy based on
Control system data need
Cost of bandwidth
Installation
Operation
Redundancy / reliability
17. Surveillance Technologies Loops
Cameras
Other technologies
Radar
Acoustic
Infrared
Other
18. Inductance Loop