Data Collection methods
Last updated
Last updated
Traffic data collection mechanisms can be classified into two methods, generally known as intrusive and non-intrusive methods. Both have their advantages and disadvantages.
The intrusive method involves placing a sensor and data logger on the road. This equipment typically includes pneumatic road tubes, an induction or magnetic loop, and piezoelectric sensors.
Pneumatic road tubes - these are rubber tubes placed across the roadway to detect vehicles as a tire passes over the tube. The air pulse is generated, recorded and processed by a meter located at the roadside. Air tubes have limited lane coverage and are suitable for ideal weather, temperature and traffic conditions.
Induction or magnetic loops - loops are fixed in the roadway and produce a magnetic field. They operate by transmitting information to a counting device placed at the roadside. Induction loops have a short lifespan because they can easily be crushed by heavy vehicles. In addition, implementation and maintenance costs can be high.
Piezoelectric sensors - this is a gadget that measures changes in pressure and acceleration using the piezoelectric effect to convert the measurement into a unit of electrical charge. It is placed in a groove along the pavement surface of the monitored lanes.
The objective is to convert mechanical energy into electrical energy. A piezoelectric sensor unit can be used to measure weight and speed. This sensor unit is available in two categories: mechanical and electrical.
Non-intrusive traffic data collection methods involve remote observations. They include the following factorial components of traffic data collection: hand counts, passive and active infrared, passive magnetic, microwave radar, passive ultrasonic and acoustic, and video image detection.
Manual counts - are the collection by trained observers of traffic data that cannot be collected by automated counts, e.g., vehicle and pedestrian classification. Commonly used materials are tally sheets and mechanical counting boards.
Passive and active infrared - this traffic data collection mechanism uses infrared energy around the detection area to record the presence of speed and type of cars passing by. Its disadvantages are that it cannot operate in bad weather and lane coverage is limited.
Passive magnetic sensors - magnetic sensors are placed under or over the roadway, which allows for counting the number of vehicles, their speed and type. The disadvantage of this measurement mechanism is that the sensors are sometimes unable to differentiate between vehicles that are in close proximity to each other.
Microwave reader - can detect vehicles in transit and their speed. The advantage of a microwave reader is that it can be used in a variety of weather conditions.
Video image detection - a video camera is placed to record the number of vehicles, their type and speed using various built-in technologies. The advantage is that AI and machine learning type computer models can be applied to improve accuracy. This is the preferred method in the 2Blox project.
We could also use Big Data. It is important to know that Big Data companies are based on a method that consists of retrieving the position of users via GPS/WIFI/Bluetooth that leave their location active. On the basis of the data collected, which is only a sample that is sometimes not representative, an extrapolation method is applied to obtain data that is "as close" as possible to reality. Using this method, the data is less accurate but affordable.