local function improveSpeed(obj)
  obj.speed = obj.speed * 4
end


for index, obj in pairs(data.raw["transport-belt"]) do
  improveSpeed (obj)
end

for index, obj in pairs(data.raw["underground-belt"]) do
  improveSpeed (obj)
end

for index, obj in pairs(data.raw["splitter"]) do
  improveSpeed (obj)
end