Some places have a bike painted on the ground to show you where to put your bike. It's usually on the middle line, if there are three lines of wire in the ground.
You can test out various triggering devices at parking lot exit gates, but they might not have the same sensitivity as traffic lights.
There's one light here that takes several minutes to change if cars are waiting, and I think the crosswalk button is broken (or given absurdly low priority). The walk light for the cross road will count down, then it will go back to a white walk guy! Traffic on the cross road is almost always light, so I just run it if no one is around. Most days I go out of my way to avoid it, though.