Where the intersections of streets, avenues, alleys, or other highways are improved, the cost of improving any intersection or any part thereof may be assessed against the lots or parcels of land abutting on each of the streets, avenues, alleys, or other highways so intersecting for a half block in each direction therefrom; provided, that for the purpose of computing assessments under this section, no block shall be considered as extending more than 1,000 feet from any intersection so improved.