Analysis of the accuracy of mapping information (using the example of motorway mapping in Ukraine and the USA)

The aim of the study is to assess the accuracy of online data in comparison with geodetic and laser measurement methods, and to determine the length of major roads by comparing them with official data from the United States and Ukraine. Main material. A comparative analysis of traditional geodetic surveys and laser scanning of US and Ukrainian roads showed almost identical results. This became the basis for assessing the accuracy of OpenStreetMap (OSM), GraphHopper (GH) and Google Maps. For each segment whose length was measured, we determined the difference in point coordinates, the squares of the point coordinate differences, the average of the squares of the point coordinate differences, the root mean square error for X and Y coordinates, the total root mean square error, and the ratio of the error to the total length of the route. The results showed discrepancies between official FHWA data, CMU data and online resources. For highways in the United States, the differences are insignificant (-1.86% to +0.25%). In Ukraine, they can reach 19.99% in some cases, which may be due to the lower frequency of updates of official sources. This underlines the need for cross-checking, in particular by means of laser scanning.Conclusions. The comparison of geodetic and laser measurements has shown their high accuracy, which allows the use of these methods to verify cartographic data. Laser scanning, presented in a digital format without intermediate digitisation steps, can serve as a control layer for determining the length of linear objects, including roads. Of the three online resources, GraphHopper shows the smallest discrepancies for both the United States and Ukraine. Ukraine’s mapping framework needs to be updated based on modern topographic and geodetic surveys, including laser scanning. Determining the exact length of transport routes is important for the effective development of the country