Radar technology in road traffic
8 applications that use radar in the transport sector.
Do you know how long radar traps have existed? The perhaps best-known radar application in the transport sector has been in use for 65 years! In the post-WW2 period, radar gained a foothold as measurement technology used in the civilian sector – first in air and ship traffic for navigation purposes, then also in road traffic. In 1957, radar technology started being used to monitor drivers’ speeds. The sensors made their début installed in cars as distance control warning devices already back in the late 1970s (source: Wikipedia). The industrial sector and researchers quickly recognized the potential radar presented put to use in road traffic. Its measuring possibilities and properties make the technology predestined for detecting vehicles.
In recent years, radar development has made great strides in terms of functionality and performance. As a result of further developments, radar’s variety of applications in traffic has broadened even further.
Despite its higher price tag, radar is often the solution of choice. Because one decisive advantage sets this technology apart from optical systems or infrared sensors: it can be used both day and night. This anonymous measuring method utilises electromagnetic waves that work no matter the lighting conditions. The radar systems are maintenance-free and operate reliably even despite dirt or difficult weather conditions. They fit perfectly into existing infrastructure and are mobile. This makes retrofitting them or temporary use along high-traffic roads easy. And there’s no need for an intrusive construction site like with induction loops.
Radar is a high-performer in street traffic. However, it’s hard to keep track of things in radar-based traffic applications. InnoSenT has a large number of radar components on offer for vehicle detection. Below, we will highlight some of the typical applications in the transport sector.
Radar technology and where it can be found in the traffic sector.
We’re presenting you with eight applications of the sensors and systems that you encounter in everyday road traffic.
1. Traffic statistics and analysis
In this radar application, the sensors detect vehicles and provide additional information about them. The radar component determines the speed, direction of movement, and distance of cars, vans, lorries, or motorcycles.
With traffic statistics, data is collected over a longer period of time. Planners and authorities use the data they obtain in their assessments and decisions. This enables them to determine, for instance, if a given lane is being used a lot, the average speed of road users, the times with the most traffic, and how often there is traffic congestion. Knowledge of traffic flow proves helpful in better planning construction sites, diversions, changes, or new infrastructure projects. The transport authorities also use such statistics to evaluate CO2 emissions. Depending on the intended use of long-term traffic analysis, the mounted sensors observe several lanes at once or individual ones, sections of the road, or entire intersections.
Radar sensors are also used for counting vehicles. For example, they can also be integrated into a guidepost at a motorway on-ramp and detect and count the vehicles entering the motorway.
InnoSenT products for this application
iSYS-5220 and ITR-3810 radar systems
The advanced 4D MIMO systems boast extensive functions for traffic statistics. It is even possible to tell the vehicles apart and categorise their type, such as car, lorry, van, or other, as well as to track their movement history.
IPS-937 radar sensor
This CW Doppler radar is ideal for installation in guideposts for easy vehicle counting.
IPS-280 radar sensor
This 24 GHz radar sensor focuses on detecting vehicles in a lane.
IVQ-3005 radar sensor
The VCO transceiver has a range of up to 300 meters and detects vehicles in multiple lanes.
2. Traffic light control
Today, various technologies can be found at intersections that enable traffic lights to be controlled based on demand. They are intended to shorten waiting times at red lights and allow green waves to facilitate traffic flow. A well-known method is induction loops, whose installation in the road surface requires extensive work.
An alternative is the non-invasive installation of modern radar units on existing traffic light poles. These recognise which the vehicles are in which lanes and detect the direction of movement. The speed and distance information indicates approximately when the vehicle will arrive at the traffic light. Radar sensors also detect the length of the queue of waiting vehicles. The evaluated data helps to ensure that the traffic light control switches at optimum times.
Some systems even go a step further. They feature a tracking function and record the road users’ turning behaviour at intersections by visualising the movement history. They also detect when vehicles are in the intersection or when broken-down vehicles are in the detection area. With the right signal processing and integration, the switching of the traffic light can even be automated in real time – to adapt to the current traffic situation.
InnoSenT products for this application
iSYS-5220 and ITR-3810 radar systems
These two high-resolution products featuring angle measurement offer the maximum possible range of functions for intersection management and advanced features such as tracking and vehicle classification.
IVS-947 radar sensor
The IVS-947 24 GHz radar sensor is suitable for traffic monitoring at small intersections. It reliably records moving vehicles in order to optimise traffic light control.
3. Road section monitoring
In this application, the radar monitors a particular section of the road, for example on a motorway. This application is usually used in combination with a camera to catch traffic law violations.
The radar detects the presence of the vehicle at two different points along the road and transmits a signal to trigger the camera. The information in the images can then be used to determine the driver’s average speed and number plate. If the driver exceeds the speed limit, the police will intervene and take appropriate action.
InnoSenT products for this application
IVQ-3005 radar sensor
This sensor allows stretches of road of up to 300 meters in length to be monitored with ease. That makes it ideal for detecting vehicles in multiple lanes.
IVS-282 radar sensor
This K band radar sensor has a range of approx. 100 m and is very well suited for monitoring sections of a lane.
The iSYS-5220 radar system
With this advanced MIMO radar, it is possible to actively regulate traffic according to the current traffic situation. The system detects broken-down vehicles on the road or in the emergency lane.
4. Traffic signs and lighting systems
You’ve probably encountered this traffic application often. Digital traffic signs show you your speed or activate as you approach the display. And they often run on radar technology, too. The radar detects the presence of a vehicle and then transmits a signal that activates the digital display.
Besides fixed-in-place installations in the transport sector, this application is also suitable for mobile use. The lit-up ‘You’re driving … km/h’ signs are usually set up in danger zones for a limited period of time to warn road users to be careful. They are often equipped with their own solar cell. For this purpose, highly energy-saving motion detectors are needed that are capable of measuring speed.
At construction sites, on the other hand, mobile lighting systems regulate traffic. Equipped with radar sensors, the construction site traffic light turns green when vehicles are waiting.
InnoSenT products for this application
IPS-280 radar sensor
With its range of 400 meters, the CW radar is specialised in measuring the speed of passing vehicles from the roadside.
The iSYS-4001 radar system
This radar system, with its IP67-tested housing, is integrated into mobile lighting systems (construction site lights).
IPS-937 radar sensor
This Doppler radar sensor is suitable for energy-efficient applications and has a medium range of up to 80 m.
IPS-354 radar sensor
The IPS-354 sensor is used to measure speeds at close range (range max. 30 meters) for digital traffic signs.
5. Street lighting
In order to reduce light pollution and save energy, cities and municipalities are already relying on state-of-the-art street lighting. Advanced systems utilise motion detectors to, among other things, automatically control the lights as needed.
Classic examples include parking lots, larger business sites, or parking garages. The lights then do not turn on until a vehicle or person arrives.
Another step is the dynamic illumination of road sections or areas of town. Thanks to radar-based motion and speed detection, the light located farther away switches on reliably – precisely coordinated with a car or lorry’s trajectory. Once the vehicle has moved out of the detection area, the light goes out.
This makes it seem like the streetlights are predicting the vehicles’ presence and accompanying them along their path. That works not only for stretches of the road, but also for entire areas of town. The detection of motion by persons or vehicles may, for example, trigger a switch from emergency to bright lighting. Dynamic and demand-oriented outdoor lighting is an important automation technology for environmentally conscious smart cities.
InnoSenT products for this application
IPS-937 radar sensor
The IPS-937 uses CW radar modulation to detect the speed and direction of travel of vehicles up to 80 meters away.
IVS-947 radar sensor
As a VCO transceiver, the IVS-947 also enables both the presence and distance of road users to be determined. With a range of 80 meters, the sensor detects not just moving but also stationary objects.
IVS-362 radar sensor
The IVS-362 radar sensor has a short range of up to 30 meters. This product is also a 24 GHz VCO transceiver and collects information about speed, distance, and direction of movement of stationary or moving objects.
IMD-3101 radar system
This motion detector’s narrow, elongated detection range of up to 80 m optimally covers alleys or roads. The included signal processing facilitates integration of the system.
6. Pedestrians in street traffic
In addition to cars, lorries, and the like, radar sensors can also detect the presence or movement of people. The technology is also used to detect vulnerable road users such as pedestrians or cyclists.
At intersections, sensors check whether there is a pedestrian waiting at the traffic lights or is still in the road. Passengers are also protected while crossing the road when a radar is installed. Because if there is still a person on the road, the traffic light doesn’t switch to green for vehicles due to the radar signal. If someone is waits at a crossing, the sensor’s signal triggers the pedestrian traffic light to change early.
In addition, the touchless switch function can be found on traffic light systems. Instead of a pedestrian touching or pressing a button, a pedestrian light can also be switched through the detection of a hand gesture. Such radar systems are installed in place of a contact switch and detect the presence of a hand or finger. This contactless control system offers users a considerable advantage in terms of hygiene.
InnoSenT products for this application
IMD-3000 radar system
The radar system has been specially developed as a non-contact alternative to push-button switches. Its design and function are conceived to accommodate contactless operation of technical devices via hand gestures.
INS radar system
This product combines two functions in one system: on the one hand, it enables non-contact control via hand gestures in the immediate proximity of the radar antenna. On the other hand, it provides the motion detector function by recognising people within a range of up to 5 or 10 meters (depending on the product variant).
IPS-937 radar sensor
Installed at intersections for traffic control or counting vehicles, the IPS-937 radar sensor can also detect people at the roadside or in the road. As a CW Doppler radar, it detects movement, direction of movement, and speed.
The iSYS-5005 radar system
The iSYS-5005 radar system offers state-of-the-art radar technology for this use case: built-in radar tracking allows the movement history of people and objects to be tracked. This enables even more accurate and reliable performance in traffic detection.
7. Access control in parking lots
Parking lot management also benefits from sensor technology. It starts the moment you enter. Access control includes controlling barriers, dispensing tickets, or counting vehicles.
For example, a radar barrier triggers a barrier to open when a vehicle passes through it. The motion detectors also provide data on the number of cars using the entrance. This information can be used to determine available parking spaces. Radar sensors also yield information about vehicles’ direction of movement. That way, drivers going the wrong way can be identified and warned.
Another example is the use of contactless switches for dispensing tickets. Instead of having to press the ticket button at the parking garage entrance manually and often uncomfortably, all it takes is a brief hand gesture in front of the sensor thanks to the touchless switch.
InnoSenT products for this application
IPS-354 radar sensor
The 24 GHz CW radar sensor can be used to activate access or exit barriers in car parks. It has a range of 30 meters and has two split antennas for maximum signal amplification.
The iSYS-4001 radar system
The iSYS-4001 radar system, protected with an IP67 housing, is ready for outdoor use. It reliably detects moving vehicles and is used for detecting drivers going in the wrong direction.
IMD-3000 radar system
The IMD-3000 radar system enables contactless ticket issuance. It has been specially developed for parking ticket machines and is easy to integrate thanks to its included signal processing.
8. Technology for catching traffic violations
Now we finally come to the classic application for radar: traffic systems for catching violations use radar technology to pursue misconduct by road users.
A radar trap measures vehicles’ speed in order to trigger a speed camera if a driver goes over the speed limit. There are fixed-in-place or mobile systems. Another example is red light cameras. Here, the radar measures vehicles’ speed and detects whether drivers are continuing over or stopping at the stop line. The system also detects unauthorised U-turns and drivers going the wrong way and can relay this information in order to impose a subsequent measure to punish the traffic violation.
Another related application is the integration of sensors into German toll columns. The radar antenna detects passing vehicles and acts as a trigger for a camera. Based on the radar signal, the camera takes a picture of a vehicle’s license plate as soon as a toll vehicle passes by. In Germany, this application applies only to lorries on certain country roads. This enables traffic along routes to be monitored and tolls to be collected.
InnoSenT products for this application
The iSYS-5220 radar system
The iSYS-5220 boasts advanced intersection management features. Among other things, it detects vehicles at the stopping line, measures their speed and tracks road users’ movement history, making the system predestined for use monitoring red lights.
The iSYS-4001 radar system
The iSYS-4001 radar system is excellent for identifying drivers going in the wrong direction. It reliably detects vehicles’ direction of movement and has a range of up to 150 m.
IPS-937 radar sensor
The IPS-937 is also used to detect drivers going the wrong way. The sensor can distinguish between approaching vehicles and those moving away and also measures vehicles’ speed.
IVQ-3005 radar sensor
The IVQ-3005 is designed for traffic monitoring in large areas, such as intersections or motorways. Its lane-specific vehicle detection makes it ideally suited for police radar traps.
IVS-979 radar sensor
The IVS-979 is also used for speed cameras – typically, however, for mobile systems that are only deployed temporarily. The precise traffic radar has a range of 150 meters and reliably determines speed, direction, and distance.
Picture Source: adempercem von getty images signature (canva.com)
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Radar for Traffic Applications
Reliable vehicle detection with traffic radars
In transport, radar technology boasts a wide variety of applications. Radar is predestined for transport monitoring and has been established for many years as an outstanding technology solution in the traffic sector. A typical example is police radar traps. However, also more complex applications such as traffic assessment and statistics for intersection management can be achieved using radar-based vehicle detection.