The imposition of busy season surcharge is an annual exercise and will remain in force from October to March, a senior railway official said. While a levy of 5 % is imposed on transportation of coal and coke, other products would be charged 7 %. Termed as dynamic pricing policy, the decision aims to overcome the effect of the recent fuel price increase. Diesel constitutes 17 % of the railways total operating cost. The surcharge will be in force from October to March. However, container traffic has been spared the surcharge. Coke and coal account for 40 % share of rail freight traffic.