Clusters of Connected Roads (IMAGE) American Physical Society Caption Clusters of connected roads. Same color denotes roads that are part of the same cluster, i.e., all connected. When there are no hacked vehicles, all roads are connected (yellow). But as there are more hacked vehicles, more colors show up, and each cluster is inaccessible from the other. When somewhere between 10-20% of vehicles at rush hour hacked, the size of the largest cluster dramatically reduces. We call this threshold (~10-15 hacked vehicles/km/lane) the point of city fragmentation. Essentially half the city is inaccessible from the rest above this threshold. Credit Skanda Vivek/ Georgia Tech Usage Restrictions Journalists may use this image only with appropriate credit. License Licensed content Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of news releases posted to EurekAlert! by contributing institutions or for the use of any information through the EurekAlert system.