Suggest use of time of day restrictions so that bicyclist have a window of time to use certain trails which minimizes chances of them running into people walking on the trail. Problem is that sight distance tend to be very short and stopping distances are relatively great with the soft surfaces of trails.
Horse people punch way above their weight and have far more public spaces available as they have been more organized and more aggressive with public officials and parklands managers. Might take a lesson from what has worked for them in the past.