Boroughs may improve streets, portions of streets or a particular width or additional widths of streets, with or without the assistance or contribution of the Federal Government, the Commonwealth, the county or a corporation occupying the thoroughfare, and may assess and collect the whole cost of improvement, the whole cost not aided or contributed or any part of the cost from the owners of real estate abutting on the improvement in accordance with Chapter 21A (relating to assessments and charges for public improvements).