Week 9 Flashcards
Three data collection technolgies?
Inductive Loop Detector Sensors
* An inductive loop detector senses the presence of a conductive
metal object by inducing currents in the object, which reduce the
loop inductance.
* Single loops can measure volume and double loops can measure
speed as well.
* It is a very cheap technology, but sometimes fails to detect vehicles
with speed below a certain threshold, and miscount vehicles with
low metal content (e.g. motorcycles).
Pneumatic Tube Sensors
* Sends a burst of air pressure along a rubber tube when a vehicles
tire passes over the tube.
* Usually measure only flow (volumes).
* Cheap but not durable, the life of tubes are less than one month.
* The tube detectors are not suitable for high flow and high speed
roads.
Video Image Processing
* Video image processors can classify vehicles by their type and report
vehicle presence, volume, lane occupancy, and speed for each class
and lane.
* The capability to register turning movements and lane changes.
* Density, link travel time, and origin-destination pairs are potential
traffic parameters that can be obtained by analysing data from a
series of image processors installed along a section of roadway.
