Dogs off leash at open park

I walk my dog to and from the Lawrence park in the Heights almost everyday. During the evening there are always people that bring their dogs out to the park and let them off the leash, play fetch, etc. I love to bring my dog and sit on the grass and just chill in peace most of the time. Lately there has been time where around 10+ dogs are off the leash running around the park. My dog is not dog friendly but can stand people. It makes me quite uncomfortable when Im just trying to enjoy my peace with the great weather, but there are dogs running around with no leash on coming up to my dog and I and freaking my dog out and making my anxiety rise. This park is not fenced in and has only one sign in the middle of the park/grass saying that people must keeps dogs on the leash at all times.

Is there something that can be done to help prevent people using this park as an off leash free roam dog park? Just need an opinion on the situation.