My field trips are 3-4 times a week, but they don't cost me anything except bus tickets sometimes, but I write off my bus tickets on my taxes as a daycare cost. We go to the nearest library one morning a week, then we have a splashpad and 4 different parks that we frequent to give us variety. Can you let your daycare families know that going to the park is considered a field trip? I don't take the children any place that costs me money and my clients are ok with that.
I don't take any chances with the children's safety so I have the youngest 2 children in my double stroller but the 3 walkers (age 2 & up) are in the backpacks with the ropes attached to my wrists. ($20 at Walmart and similar places, also a tax writeoff) Our roads are too busy so I would never consider just letting the children hold onto the stroller without being attached to me.