Additionally, you could go under the fences if you parked a heavy vehicle next to them and crawled below it.
Don't forget walking below the city entering the spot where the water was solid on northwest pier.
And finally, if you left the train in the precise spot, you could exit the train on top of the (eletrified) tracks and would not die.
I later got my hands on a copy of GTA2 and played that a lot, behind my parents' back of course