On big hairy intersections where I know the cars are too fast/too many and too many lanes (4 lanes of traffic would definitely qualify for me!!!) I get off the bike and walk in the cross walks.
I commute on the road. The last time I rode on the sidewalk it was very dark and I didn't feel safe on the road. I went about 6 or 7 mph, and stopped at each cross street. Verrrrrrry carefully.
At a stoplight when there is a line of cars I pull up behind the last car. I get centered in the lane behind that car (my lane, my spot, everyone see me in it!) and stay centered until I'm thru the intersection. Then I'll move back to the right.
(around here in my small-ish part of town cyclists cutting to the front of the line at a stop light is kind of considered rude. Plus, a car or two at the front might be turning right and you don't want to end up next to them and have them turn into you. And if you sneak up on the right the cars you sneak up on might not see you.)
"If Americans want to live the American Dream, they should go to Denmark." - Richard Wilkinson