Maharashtra PWD Minister AshokChavan on Tuesday demanded that the Centre give the state Rs 20,000 crore for national highway works.He made the demand during a video conference meeting of state PWD ministers with Union Minister for Road Transport and Highway Nitin Gadkari.Chavan said highway works were moving at a snail's pace and facing difficulties.Contractors who are not adhering to schedules should be blacklisted, he told the Union minister.