Soapbox riders in Perú, on the road from Huánuco to Tingo Maria, where the highway from the Pacific coast across the Andes finds its way towards the Amazon lowlands. This is near the top of the last mountain pass. From there, soapbox riders can enjoy a vertical 1000 meters of gravity assisted ride.
Since these kids help stranded truck drivers along the road, they're called bomberos (firemen). They transport drinks, food and spare parts to broken trucks.
Thanks to ZU from Perú for additional info:
"I usually use that highway go to work. I saw a lot of those cases of children with their skateboard or a board with wheels (artesanal) (those wheels are metallic and they tolerate the speed) they have had many fatal accidents and some times they do it for work like "fireman", I work for this highway 4 years, most of them are poor children that don't have money neither for the bus ticket, to move from a place to another in long distances and some for "enjoy"."