Inductive Loops vs LiDAR Technology for Traffic Detection and Actuation
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Inductive loop technology has established itself as the leading traffic detection and actuation technology for years. Developed specifically to detect the presence of passing vehicles at the intersection, they are the most common traffic sensors.
However, the evolving needs of cities and transport agencies combined with the continuous advancement of technology have led us to many superior technologies able to detect multiple types of road users and optimize traffic flow in a whole new way.
Drawbacks of Inductive Loops
While inductive loops have helped detect passing vehicles and improve traffic flow for years now, they present several significant disadvantages:
- They are costly to install and to maintain
- Installing inductive loops requires cutting into the pavement to lay the loops of wire. On top of requiring lane closures, this process is labor-intensive and involves specialized equipment to ensure precise placement.
- They only have a lifespan of 3 to 7 years
- Over time, the loops can suffer from wear and tear due to heavy traffic, weather conditions, or road repairs. This can cause the loops to fail, requiring repairs or replacements, which are costly and disruptive.
- They cannot distinguish between types of vehicles
- Inductive loops only sense that a vehicle is passing by but cannot know if the vehicle is a car, a bus or a truck. Therefore cities do not have a clear picture of how people move through a city
- They cannot detect vulnerable road users like pedestrians and cyclists
- Inductive loops simply cannot detect pedestrians crossing an intersection or a cyclist passing on the side of the road, losing precious traffic data.
- They do not provide traffic data and analytics
- Incorporating multimodal data into traffic optimization efforts enables cities to create a more efficient, safe, and sustainable transportation environment, enhancing the quality of life for all residents.
LiDAR Technology
LiDAR (Light Detection and Ranging) technology is increasingly being used at intersections to detect, classify, and analyze road users for improved traffic actuation and intersection management.
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How LiDAR Works at Intersections
- Detection of Road Users:
- High-Resolution Mapping: LiDAR sensors emit laser pulses that bounce off objects and return to the sensor, creating a high-resolution 3D map of the environment. At intersections, this allows for the most precise detection of all road users, including cars, buses, trucks, cyclists, and pedestrians.
- All-Weather Functionality: Unlike cameras, LiDAR is not affected by lighting conditions (like darkness or glare) and can function effectively in various weather conditions, including fog, rain, or snow.
- Classification of Road Users:
- Object Differentiation: LiDAR systems use algorithms to differentiate between different types of road users. They can identify and classify objects based on size, shape, and movement patterns, distinguishing between cars, trucks, bicycles, and pedestrians.
- Behavior Analysis: Beyond simple classification, LiDAR can analyze the behavior of these road users. For instance, it can detect whether a pedestrian is waiting to cross the road or if a vehicle is preparing to make a turn.
- Real-Time Analysis for Traffic Actuation:
- Dynamic Signal Control: LiDAR provides real-time data that can be used to adjust traffic signals dynamically. For example, if the system detects a group of pedestrians waiting to cross or a queue of vehicles building up, it can extend green light durations or prioritize certain movements to reduce delays.
- Conflict Detection: By continuously monitoring the intersection, LiDAR can detect potential conflicts, such as a vehicle running a red light while pedestrians are crossing. This information can be used to trigger alerts or adjust signal timing to prevent accidents.
- Data Collection and Long-Term Analysis:
- Traffic Flow Monitoring: LiDAR collects detailed data on traffic flow patterns over time. This data can be analyzed to identify trends, peak usage times, and areas of congestion, allowing for more informed decision-making in traffic management.
- Safety Enhancements: The data from LiDAR systems can also be used to improve intersection design and safety. For example, if the technology consistently detects close calls between vehicles and cyclists, city planners might consider installing protected bike lanes or adjusting signal timings.
Benefits of Using LiDAR at Intersections
- Precision: LiDAR’s high-resolution mapping allows for the precise detection and tracking of all road users, leading to more accurate traffic management.
- Easy to install and maintain: Installed above ground, this type of system is non-intrusive and doesn't require any road work to be installed or maintained.
- Safety: By detecting and classifying road users in real-time, LiDAR enhances the safety of intersections, reducing the likelihood of accidents.
- Efficiency: LiDAR enables more responsive traffic signal control, reducing wait times and improving traffic flow.
- Scalability: The data collected can be used to optimize not just individual intersections but entire traffic networks, leading to city-wide improvements.
LiDAR: A Cost-Effective Alternative to Inductive Loops
In summary, Inductive loops have been a popular choice for about 60 years and have been adopted in many countries. They accurately provide information about the number of vehicles that have passed over the loops’ detection area and can be integrated into traffic light controllers for traffic actuation. On the other hand, inductive loops cannot provide information about the type of road user, speed, trajectories and other detailed traffic information that is vital for improving road safety. They are also expensive to install and maintain.
SIMPL is a comprehensive and cost-effective solution to detect and analyze the presence of all road users. Real-time data can be shared with the city planners as well as traffic light controllers for optimized actuation.