Remote Traffic Microwave Sensor Manual Computer Vision

This suggests that the level of inaccuracy is being masked by the positive and negative counting errors cancelling each other out.

Remote Traffic Microwave Sensor Manual Computer Vision

Manual Computer Vision (Video) Pneumatic Tubes Piezoelectric Inductive Loop Magnetic Acoustic Passive Infrared Doppler Radar Manual counts A simple but accurate method of traffic counting comprises people manually counting vehicles.

A person either uses an electronic hand held counter or records data using a tally sheet.

They may stand at the side of the road, or, more commonly watch a video of the road and count from that.

In tests manual vehicle counting was 99 accurate over the counting period.

With manual counts a small sample of data is taken typically during less than a day and results are extrapolated for the rest of the year or season.

This is where errors are introduced as the small sample is rarely exactly representative of the the entire year.

Vehicle Detection using Computer Vision Obviously manual counting is labour intensive.

Systems are now available that will automatically analyse video pictures as cars pass by cameras, detecting vehicles with a similar accuracy to that of people watching the video.

This vehicle counting method has several advantages over other automatic systems.

It is cost-effective as it can count in many directions at once: only one camera is needed for several lanes or exits at a junction.

Traffic counts are uploaded in real-time via the internet, so traffic engineers can view live and historic counts from their web browsers.

Counts are easily verified simply by watching the video and checking the automated counts.

Video traffic counting typically takes place continuously, year round, giving precise figures.

This method of vehicle detection is often used in smart cities the count data is made available over the cloud wherever it is needed.

Useful for monitoring congestion, car parking and assessing traffic control initiatives.

Pneumatic Road tube counting This has for many years been a popular method of vehicle sensing.

Here one or more rubber hoses are stretched across the road and connected at one end to a data logger.

When a pair of wheels hits the tube, air pressure in the squashed tube activates the data logger which records the time of the event.

A pair of tubes can be stretched across several lanes of traffic.

The data logger can establish vehicle direction by recording which of a pair of tubes the vehicle first drives over.

This has the drawback that if two vehicles cross the tubes at the same time then the direction cant be accurately determined.

Should two cars be very close together when they cross the tubes, the system may see them as one multiaxle vehicle.

Studies show though, that the absolute error of a typical 15-minute count averaged closer to ten percent.