Painting in crowded public areas can be challenging, these public spaces are a little different than just painting outdoors in places where you have little contact with other people.
I’m lucky that when I started painting outdoors many years ago. I was living in Napa California and so got used to being surrounded by crowds of people as I worked. There were no places you could go in the Napa Valley without attracting onlookers. I quickly developed the ability to paint and talk to people and now I enjoy meeting people while I paint. I can generally stay pleasant while working as long as people are not overly rude or clueless about respecting my personal space.
I have never understood any artist who gets upset with bystanders interested in their art, especially when that painter is so visible and chooses such a public location in the first place. I've even witnessed bad behavior at Plein Air events by artists who obviously didn't belong there snapping at quiet onlookers. My rule of thumb is to keep your bad attitude at home. If you don’t like or can’t handle communication while you paint then go paint in a more remote location where you can expect very little interaction while you work.
Part of the key to being in very public areas is keeping a small footprint. When a place is overly populated its best to not have too much gear where distracted people might not notice it and end up tripping over it or stepping on it.
In areas that get a lot of traffic I use a smaller setup, this way I can carry all of my gear in a small backpack. This includes my palette/ pochade box, all my paints and brushes, paint scraper , utility tool, mineral spirits and brush washer, a tripod, a small stool (if I choose to sit) paper towels, garbage bags, food and water, sketchbook, business cards and fliers, sunscreen, bug spray, rain poncho, nightlight and up to 6 to 10 panels depending on the size. That number of panels is more than enough for a day of outdoor painting. Anything that can be ruined by getting wet goes into a ziploc plastic bag.
Whether I stand or sit when I set up, I place everything between me or directly under my easel so that no one can step on it or trip over it. If I’m not using something it stays in the pack not spread out all over the ground around me. When I take something out I put it back in the same spot so I know where to find it. By staying organized I get to spend my time painting not rummaging for something in my pack. By keeping things in their place until I need them it also allows me to pack up and break down very quickly.
Here is what it looks like all spread out on the floor. Total weight for this is only 20 lbs. including the pack. It is light enough that I can go on an extended hike and have everything I need for a days’ worth of painting.