There are a lot of car crashes on the Portway. I don't know how many end in fatalaties, but I feel like I hear about at least one every year. In a luckily non-fatal crash in 2019, an ambulance even managed to crash, ending up on its side.
I think that non-emergency vehicles probably tend to drive far too fast for the Portway when it's quiet as it looks like a nice fast road, but it clearly has some well-disguised dangers. Either that or they're all pissed.