1. A computer-implemented method comprising: receiving, by one or more configured computing systems, indications of multiple road segments of multiple related roads; obtaining, by the one or more configured computing systems, information about expected traffic conditions for each of the road segments for a current time, the expected traffic conditions reflecting traffic conditions that are normal for the road segments at the current time; obtaining, by the one or more configured computing systems, information about target traffic conditions for each of the road segments for the current time for comparison to the expected traffic conditions for the road segments, the target traffic conditions reflecting actual traffic conditions on the road segments; for each of the multiple road segments, comparing, by the one or more configured computing systems, the target traffic conditions for the road segment for the current time to the expected traffic conditions for the road segment for the current time to automatically determine whether the target traffic conditions are abnormal with respect to normal traffic conditions for the current time; and providing, by the one or more configured computing systems, indications of the road segments whose target traffic conditions are determined to be abnormal for the current time to facilitate travel on the roads.