On the topic of this being unblocked though, Cops have recently started to become smarter in blocking all entrances when someone goes down. Take a situation almost a week ago when I was wanted and was running from essentially all of PD + a heli, I had lost all ground units and went into the sewers on my bike but the heli had still seen me go down, because of the large PD presence recently they blocked essentially all exits including the one which you can drive into with a car behind Mission Row in the River. Even if maybe 1/2 of the closed off entrances were opened it would be easier to drive in and out if you are using a car. (I was on my bike)
shoutout sanchez though for being big brain and blocking me off