There have been 160 deer collisions on the A22 this year
A campaign for dedicated crossings for horse riders in Ashdown Forest is being stepped up after a boy was hit by a car and his horse fatally injured.
The young rider was struck as he crossed the A22 with his mother, who was also on a horse, on Saturday.
Deborah Waygood, of the Ashdown Forest Riding Association, said a custom-built road crossing for horses was essential.
The forest, on the Kent/Sussex border, is renowned for road accidents, which often involve the deaths of deer.
Ms Waygood said the association had been campaigning for traffic- light controlled Pegasus Crossings for a number of years.
Control buttons on Pegasus Crossings are higher than on a pedestrian crossings and feature green and red horse-shaped indicator lights.
She said: "We've sited four different places where they would be useful - one close to where the accident happened, two sites south of Nutley, and one on the B2026 near Duddleswell tea rooms.
"The A22 stretch where the accident happened is the only stretch of road across the Ashdown Forest where there isn't a 40mph limit and the traffic is very fast."
Ms Waygood said an underpass was another good idea for the road, where there had been 160 deer collisions this year.
"I think the deer would definitely go through the underpass, and obviously everybody else would use it as well," she said.
But Dr Hew Prendergast, Clerk to Conservators of Ashdown Forest, added that while both options were possible the question of cost was paramount.
"The idea of the underpass itself [for deer] wouldn't work - it would need extensive fencing on both sides of the A22 to channel the deer through the underpass.
"Personally I think we've got to get to the core of the problem with deer, and that is the huge numbers that are around," he said.
Dr Prendergast told BBC Sussex that he felt it would be better if some of the deer were killed humanely rather than being "mown down rather indiscriminately on the roads".