This study found that equestrian trail users strongly prefer to visit trails specific to horses and are willing to pay a user fee to access them, but this preference is less pronounced for more experienced riders. Riders are also willing to pay more to ride on longer trails and on trails with scenic views.
Hu, W., P. Qing, J. Penn, M. Pelton, and A. Pagoulatos. 2014. “Rider preferences and economic values for equestrian trails.” Journal of Environmental Planning and Management ahead-of-print (2014): 1-19.