Randy, in cases where "seconds can mean life or death," Providence has LifeFlight helicopters. Helicopters don't care much about street traffic, I've found. 
Besides that, if there was a sizable pattern of road congestion causing loss of life, Providence would have presented those numbers to the various boards when it was campaigning for this extension, and thus would be a matter of public record. There wasn't, they didn't, so there isn't.