It takes about 15 minutes to cross the Penang bridge, sometime takes about 10 minutes longer if there are heavy traffic especially during peak hours. So there's really no need for make a pit stop while crossing the bridge.
Now the bridge is under construction due to expanding another lane so it gets a little bit congested sometimes. Recently they closed down 2 lanes and left only 1 lane open so it got really jammed. The bad news is I was on the bridge at that time with 3 other friends in the car. We got stranded on the bridge for about an hour, and to make things worst I really got to pee and there no place for me to do that.
To cut the story short, I took a pee right on the bridge in the middle of the traffic jam with hundreds of cars and thousand of eyes looking at me. I was so embarrassed but hey, I got to do what I got to do okay, and I can't do it in my friend's car rite?
Imagine if there is an accident and the road got blocked for few hours and you have to shit, lucky for me I'm a guy and just have to pee. I think they should provide toilet on the bridge. Just in case.