Telraam citizen science traffic counts, Ljubljana, 2021: raw single-sensor exports from the WeCount H2020 project

This dataset contains the raw hourly Telraam sensor exports for four Ljubljana streets, collected during the WeCount Horizon 2020 project ("Citizens Observing UrbaN Transport", Grant Agreement No. 872743) in 2021. **Streets covered:** - Zoisova cesta primary sensor (Telraam segment 9000000002), Faculty of Architecture, Zoisova 12- Zoisova cesta control sensor (segment 9000000728), Faculty of Architecture, Zoisova 12, operational Nov 2020 – Jan 2021- Karlovška cesta (segment 9000000649), private dwelling on Karlovška 24- Grubarjevo nabrežje (segment 9000000989), eastern bank of the Gruber canal- Slovenska cesta (segment 9000000619), central pedestrianised corridor **Format:** Each file is provided in both Excel (.xlsx) and CSV (.csv) format. Counts are at hourly resolution; rows include the Uptime fraction and counts (with directional breakdowns) for pedestrians, cyclists, cars, and large vehicles, plus per-hour car speed distribution in 10 km/h bins. **Coverage:** 1 January – 31 August 2021 for Zoisova, Karlovška, and Grubarjevo; 1 January – 31 May 2021 for Slovenska (sensor disconnected from late May 2021 onward). **Relationship to existing publications:** This deposit complements the Data in Brief publication of the southern inner ring road (Ažman Momirski & Berčič, 2022, https://doi.org/10.1016/j.dib.2022.107878) and the associated Zenodo dataset (Berčič, 2021, https://doi.org/10.5281/zenodo.5583921). The present release provides: 1. raw single-sensor exports without the cleaning or aggregation applied to the southern-ring publication,2. extended geographic coverage to two streets outside the southern ring (Grubarjevo nabrežje and Slovenska cesta), and3. the empirical foundation for the analytical methodology paper Berčič (forthcoming, *Urbani izziv*). Users seeking authoritative cleaned counts for the southern ring should consult the Data in Brief deposit. Users seeking the raw platform output should use the files here. **Known limitations:** Three caveats affect interpretation. First, the 2021 data fall almost entirely within the Slovenian COVID-19 restriction period and are not representative of pre- or post-pandemic conditions. Second, the Telraam v1 classifier has known systematic biases (groups of cyclists may be classified as a single car; shadows cast by low sun parallel to the road may inflate the large-vehicle share). Third, sensor uptime varies across the four streets and within the observation window; the Slovenska sensor ceased returning valid data after late May 2021, and the Grubarjevo sensor has reduced uptime in July 2021. The dataset is provided as the platform returned it, without imputation or post-hoc correction. Users are advised to interrogate the Uptime column before computing aggregated statistics. See README.md inside the archive for the full coverage table, the data dictionary, and citation guidance.