Simple mod that re-balances top speed values for some fuels to speed up transit.

All of the code:

data.raw["item"]["wood"].fuel_top_speed_multiplier = 1;
data.raw["item"]["coal"].fuel_top_speed_multiplier = 2;
data.raw["item"]["solid-fuel"].fuel_top_speed_multiplier = 3;
data.raw["item"]["rocket-fuel"].fuel_top_speed_multiplier = 5;
data.raw["item"]["nuclear-fuel"].fuel_top_speed_multiplier = 5;