The Hellenic Institute of Transport (HIT/CERTH) and the Hellenic Institute of Transportation Engineers (HITE) co-organized the 11th International Congress on Transportation Research (ICTR 2023), which was held on 20-22 September 2023 in Heraklion, Greece. The spotlight theme of the 2023 Congress was “Clean and Accessible to All Multimodal Transport“. Special focus was given to innovative and sustainable traffic safety concepts in Greece and worldwide. NTUA contributed actively with the following 16 scientific papers and presentations: