Road surface markings, like symbols and line markings, are vital traffic infrastructures for driving safety and efficiency. However, real-world conditions can impair the utility of existing road markings. For example, adverse weather conditions such as snow and rain can quickly obliterate visibility.
We propose a novel MagnETic ROad marking system (METRO) for robust recognition of road markings at low cost and high deployability. METRO pairs (a) easily deployable passive magnetic road markings with (b) an automotive-grade magnetic sensing framework that detects and interprets these markings. The design of METRO addresses several real-world challenges, such as mitigating the impact of magnetic disturbances, lowering deployment costs, and enhancing the durability of magnetic tags. On-road field tests of METRO demonstrate an overall accuracy of over 96% in interpreting various road markings in adverse conditions with less cost (only \$0.17 per meter) than traditional road markings (\$0.21–7.70 per meter). Our field evaluation of METRO over one month demonstrates the practicality and robustness of METRO in real-world settings. Specifically, we observed no performance degradation in the METRO sensor array and no damage or demagnetization to METRO’s magnetic tags.