Intersection Signal Data Can Filter Access Routes Before a Site Visit

Intersection survey results are now in one file

The Ministry of Land, Infrastructure and Transport, the Korean government ministry responsible for national transport policy, has released nationwide intersection data collected through traffic impact assessments. Along with project locations and intersection names, the data includes road layout, signal equipment type, survey date and time, signal phases—the order in which signals turn on—and green and yellow durations. The Public Data Portal says red-light duration is also available, but that field does not appear in the published column list. It needs to be checked in the actual file.

The public file contains 204,544 rows, with surveys conducted from February 2004 to July 2025. One intersection can appear in multiple rows depending on survey time and signal sequence, so this should not be read as data for roughly 200,000 separate intersections. It is still too large for people to review row by row, which creates a need for tools that can search and map it.

The data covers the whole of Korea and is updated annually. It is therefore not real-time information about the signal currently operating at an intersection. It is better suited to identifying intersections that need checking based on past survey results. A service should show the survey date rather than hide it, so users can see how far it is from the present.

The file can be downloaded free of charge without logging in and opened in spreadsheet software such as Excel. A programmatic connection that imports the data automatically requires account registration, an application to use the data, and an authentication key. The public page does not state a specific usage limit, so this should be checked before operating an automated connection.

The published column list does not include latitude and longitude. Someone still needs to convert project locations and detailed addresses into map coordinates, then compare those locations with the surveyed intersections. Some projects may lack signal sequences and durations. That makes it more appropriate to begin with a service that finds places with available data first, rather than one that claims seamless nationwide guidance.

Bring an address-copying workflow into one screen

Consider a dispatcher at a field repair company with 12 employees. When a customer leaves an address, the dispatcher copies it from the intake screen into a map, then checks street imagery for the access road and major intersections. If the decision is difficult, they ask a field technician through a messaging app and write the response back into the dispatch sheet.

In this process, the same address moves between the intake screen, map, and dispatch sheet. A technician’s experience that an intersection is complicated stays in a chat conversation, and another dispatcher repeats the same check on the next visit. If vehicle entry and pedestrian access are recorded together, it also becomes unclear which risk was checked.

Adding intersection data changes the first step. When a customer address is entered, the system can first show nearby rows that contain the intersection name, layout, signal equipment type, survey date, and green and yellow durations. Rows with old surveys or missing signal durations can be marked “on-site check required.”

The dispatcher no longer needs to switch between a map and a long source file. On one screen, they can review the visit address, nearby intersection candidates, the age of the data, and notes from previous technicians, then decide what to check first. The decision can go directly into the dispatch note without being copied elsewhere.

The important point is not to judge safety automatically. This data alone cannot show crosswalk locations, sidewalk width, curbs, construction conditions, illegal parking, or actual pedestrian signal duration. Its reliable role is narrower: identify intersections that appear complex and locations where data is old or incomplete.

Some work clearly remains with people. Dispatchers or technicians need to review street imagery, call customers or the relevant authority when necessary, and check important visits on site. The terms of use and cost of Korean map services used to convert addresses into coordinates also need separate review.

What changes, in the end, is not the on-site check itself but the order in which places are checked. Instead of investigating every address equally deeply, a team can start with visits where data is old or intersections are complex. This small connection can reduce work that was previously fragmented across intake tools, maps, messaging apps, and dispatch sheets.

How signal and map data have been connected elsewhere

“Traffic Light Info 2.0” in Ingolstadt, Germany, provides city signal status free of charge as an access point for app developers and vehicle manufacturers. Vehicles can use the information to provide recommended speeds timed to green signals or the remaining time until a red signal ends. The project began by opening city signal information for external services and extended to a plan to convert 160 intersections across the city into smart signals.

The key lesson from this case is that the city did not build every driver-facing screen itself. The city provides signal data, while car companies and app developers adapt it for their own interfaces. Korea’s data, however, consists of annually updated historical survey values, so it cannot immediately support the same kind of real-time countdown.

The “SmartCross” pilot in New York, United States, used intersection layout and real-time signal status on smartphones to guide blind people across streets using audio and vibration. Twenty-four blind participants took part at four connected intersections. Eighty-three percent said they would feel safer or somewhat safer using the app, and 71% said it increased their confidence in crossing compared with existing assistive tools.

By contrast, 75% of participants experienced location-accuracy problems. Signal data alone can still lead to incorrect guidance when a smartphone cannot accurately determine a user’s location and direction of travel. This is a reason to begin a similar Korean service with a tool for finding intersection candidates and accumulating field-survey results, rather than promising automatic crossing guidance from the start.

Things you could build from this now

1. Pre-departure intersection cards for field technicians

• What it does: Combines intersection layout, signal data, survey date, and technician notes near a visit address into one card attached to a dispatch sheet.
• Who uses it: Dispatchers at small field repair companies that install boilers, water purifiers, or telecommunications equipment across unfamiliar residential and commercial areas.
• Why now: The nationwide data is available as a free file, allowing teams to identify places to check without surveying every area themselves first.
• First screen: Next to today’s visit-address list, show labels for “data available,” “old survey,” “signal duration missing,” and “technician check complete.”

2. Field-survey list for wheelchair and stroller routes

• What it does: Identifies intersections with complicated layouts or insufficient signal data between an origin and destination, then creates an order for field surveys.
• Who uses it: Staff at local groups mapping wheelchair routes around welfare centers or surveying stroller walking routes.
• Why now: Surveyors can narrow down intersections to inspect before walking every side street, then add curb, slope, and sidewalk-width information separately.
• First screen: After entering an origin and destination, show “intersections to check first,” survey dates, missing information, and a button to upload field photos below the map.

3. Access-check notes for prospective shop locations

• What it does: Creates site-visit notes for each prospective shop address by combining nearby intersection data with questions to verify in person.
• Who uses it: An operator planning a prepared-food shop without delivery service, where many customers are older adults or people visiting with strollers.
• Why now: Before signing a lease, they can compare access conditions using intersection survey records instead of judging from maps alone.
• First screen: Place three candidate shops side by side and show the nearest surveyed intersection, data year, whether signal duration is available, and items to inspect on site.

4. Traffic-survey data cleanup board

• What it does: Connects project locations and intersection names in the source file to map candidates, while allowing users to review duplicate rows and missing signal values.
• Who uses it: Staff at small traffic design offices that download traffic impact assessment data across several regions and organize it between Excel and maps.
• Why now: More than 200,000 rows are public, but location cleanup and grouping by intersection remain, leaving room to reduce repetitive work.
• First screen: After entering a project address, show intersection candidates for that project, rows by survey time, missing signal durations, and map-link status in one place.

Why this matters where you are

Korea’s annual, nationwide publication of historical intersection survey data is a Korean condition, not a real-time signal feed. Check whether your own market publishes comparable intersection, road-layout, or signal-survey records, and whether they include dates and usable location data. If the records are incomplete or old, they can still help prioritize field checks rather than replace them.

What to check today

Download the file from the Public Data Portal and search for five addresses you handle regularly. If you can connect at least three of them to a specific intersection and confirm both the survey date and whether signal duration is available within 30 minutes, a small search screen may be worth building. If fewer locations connect, narrow the scope from nationwide route guidance to a checker for whether data exists in a specific area.