What is map matching? Explanation of its mechanism and applications.

Map matching is a technology that corrects location information obtained from GPS or other sources to match it with roads and routes on a map.

GPS uses radio waves from satellites to determine location, but the acquired location information may have errors due to the GPS performance of the device, radio waves, noise, and other factors.

Due to GPS measurement and sampling errors, problems can occur in navigation apps and car navigation systems, such as vehicles being displayed off-road on maps. Therefore, correction processing is necessary. Map matching is the process of performing this correction processing to match the map data.

There are two types of errors caused by GPS: "measurement error," where the position measured by GPS deviates from the true position, and "sampling error," where data is lost between recording intervals.

The map matching mechanism works by comparing GPS coordinates with road network data to estimate the optimal route based on the direction of travel and speed. However, due to errors in the data obtained from GPS, vehicles may deviate from the road or be displayed on the wrong road. Therefore, it is necessary to compare the data with surrounding road network data to identify the most appropriate road segment.

When identifying road segments, we don't simply select the closest road. We also consider information such as direction of travel and speed to estimate the actual road being traveled on and correct the coordinates. For example, in places where elevated highways and ground-level roads overlap, or at complex intersections, judging solely by straight-line distance could result in displaying a completely different road.

Therefore, map matching analyzes not a single "point," but a movement trajectory, which is a continuous sequence of location information from the past to the present. In addition to this movement trajectory, information such as direction and speed of movement, as well as conditions on the map data such as "one-way streets" and "road connections," are comprehensively considered to accurately estimate the road being traveled and correct the coordinates.

In what situations is map matching actually used? Here are three typical use cases:

<Main use cases for map matching>

• Car navigation system
• Vehicle management and delivery route management
• Location information analysis/traffic analysis

Car navigation system

Car navigation systems accurately display the vehicle's position on the road through map matching. Even in sections where GPS signals cannot be obtained, such as inside tunnels, the current location can be estimated based on previous location information and road data, enabling uninterrupted navigation.

Furthermore, accurate location display allows for appropriate guidance on right and left turns at intersections and lane changes. In addition, map matching enables appropriate navigation based on the map, making it a crucial technology that contributes to ensuring the safety of autonomous driving.

Vehicle management and delivery route management

Map matching enables accurate recording of driving history and real-time situation monitoring in vehicle management and delivery route management. By utilizing map matching, you can monitor the situation in real time, record the roads traveled, and use this information for operational analysis.

Furthermore, it can be used to optimize delivery routes and improve the accuracy of arrival time predictions, leading to improved operational efficiency.

Location information analysis/traffic analysis

In location and traffic analysis, map matching plays a crucial role in transforming vast amounts of GPS data into road-level statistical information. By linking large amounts of GPS tracking data to roads using map matching, statistical analysis becomes possible.

Furthermore, in the analysis of people flow data, which includes information such as the location, time, and attributes of people's movements, mapping movement routes to roads and facilities will allow for highly accurate insights to be obtained.

Furthermore, by applying map matching technology, it's possible to determine which subway line a user is on. For example, by matching points where the GPS signal disappears (entrances to the underground) and points where it reappears (exits to the surface) with route data, it's possible to estimate which line a user is on.

When implementing map matching functionality, using API services is highly effective. A major advantage is that it eliminates the need to develop complex algorithms in-house, allowing for quick and low-cost implementation.

A concrete example is the "Map Matching API" provided by GeoTechnologies, Inc.. The Map Matching API is a function of the corporate-向け map cloud service "MapFan API" that corrects latitude and longitude acquired from GPS devices to match GeoTechnologies, Inc.' road network data. One of its features is that it not only links the data to the road network data, but also takes into account road information such as one-way streets when making corrections.

The "Map Matching API" allows you to obtain attribute information such as road name, road type, Speed limit, and number of lanes, along with corrected location information.

This allows delivery managers to track the precise location of each vehicle in real time, contributing broadly to efficiency improvements in the logistics industry, such as acquiring driving logs and identifying dangerous driving practices. Furthermore, GeoTechnologies, Inc.' unique strength in maintaining maps and road data for all of Japan, the system is automatically updated with the latest road information every month, ensuring that highly accurate data is always available.

Map matching is a technology that corrects positional errors caused by GPS and determines the precise location on the road network. One of its features is that it doesn't simply correct to the nearest location, but also considers information such as direction of travel and speed to estimate the actual road being traveled on and correct the coordinates accordingly.

It is used in a wide range of fields, including car navigation systems, vehicle management, and location information analysis, contributing to the overall improvement of location information service accuracy.

When considering ways to improve operational efficiency in the logistics industry or develop services utilizing location information, the introduction of map matching is essential. If you are considering implementation, please feel free to contact GeoTechnologies, Inc..

Click here for details on MapFan API, which allows you to use the "Map Matching API".

What is map matching?

Map matching is a technology that corrects location information obtained via GPS or other means to match it with roads and routes on a map. GPS location information can be inaccurate due to the GPS performance of the device, radio waves, noise, and other factors, sometimes resulting in incorrect display on map data. When location information is not accurately displayed, instead of simply selecting the nearest road, the system considers information such as direction of travel and speed to estimate the actual road being traveled on and corrects the coordinates accordingly.

What is map matching useful for?

Map matching allows for accurate, real-time tracking of vehicle locations, making it useful in car navigation systems, vehicle management and delivery route management for transportation companies, location analysis, and traffic analysis. It contributes to improved operational efficiency by optimizing delivery routes and increasing the accuracy of arrival time predictions.

How do I implement map matching?

When implementing map matching functionality, you can either develop it in-house or use an API service. For quick and low-cost implementation, an API service is recommended. For example, GeoTechnologies, Inc.' "Map Matching API" allows you to obtain attribute information such as road name, road type, Speed limit, and number of lanes, along with corrected location information.