Preliminary cost estimation of Rs 1,680 million for Pirwadhai flyover and underpass project prepared by the National Logistic Cell (NLC) was returned by the Punjab Highway Department after raising some objections. Sources said that construction work would be started on the Pirwadhai Flyover and underpass in October, but IESCO main supply line and Sui gas main distribution junction fall in the project, so shifting of supply lines could delay the start of the mega project.