At a recent podcast in Lifo, NTUA Professor George Yannis emphasized the importance of implementing city-wide 30km/h speed limits in Greece. Drawing from extensive European data and simulation studies, he noted that city-wide 30km/h speed limit is the since-long waited single road safety measure with such a significant benefit at such a low cost. The myth that lower speed limits significantly delay travel times was refuted by evidence showing only negligible differences and even long-term traffic improvement. The necessity for a cultural shift toward sustainable transport and reduced car dominance was highlighted, advocating for reclaiming public space and enhancing public transport. The innovative and impactful NTUA campaign of 30 Marathons in 30 months, implemented by Prof. Yannis, to actively promote the adoption of 30km/h speed limit in all cities worldwide was also discussed. Lastly, he concluded by stressing the urgent need for integrated transport policy and serious action to tackle traffic congestion and improve mobility in Greek cities. The full article and the related audio-podcast are now available.