Before signing and recording of final subdivision plats, the applicant shall have installed, under the inspection of the Township Engineer, all improvements required unless the applicant has posted and the governing body accepted a performance guarantee providing for such installation. The amount of the guarantee shall be determined by the Township Engineer, not to exceed 120% of the estimated cost of constructing the improvement, including: streets, curbs, grading, pavement, gutters, sidewalks, streetlighting, surveyor's monuments, water mains, culverts, storm sewers, sanitary sewers, drainage structures, soil erosion and sediment control devices, public improvements of open space, traffic street signage, pavement markings, shade trees and, in the case of site plans only, other on-site improvements and landscaping. The Township Engineer shall prepare an itemized cost estimate of the improvements covered by the performance guarantee, which itemized cost estimate shall be appended to each performance guarantee posted by the obligor.