The event, one of the largest in the of its kind in Europe, starts on 4 June.
Organisers said that in 2014 there had been safety issues on the A685 when people arrived too early with trailers.
Restrictions will be put in place to reduce roadside parking, but there will be spaces provided for traditional bowtop caravans and horse grazing.
Dr Robin Hooper, chief executive of Eden District Council, said: "People arriving too early with trailers are not respecting the fair and are disrupting the outlying communities around Appleby.
"So please, plan your journey well and use the stopping places provided."
Gypsies and travellers planning to attend the Appleby Horse Fair in Cumbria have been warned not to arrive before it begins.