Sidewalks are kind of expensive

(2009). Green Values. http://greenvalues.cnt.org/national/cost_detail.php

There is no author of this website as it is a collection of data to help compare costs of maintenance for different components of an urban area. The website provides survey results that give an accurate interpretation  of the costs of the different components. The purpose of the site is to inform viewers the potential cost of different urban components while making it easy to compare the costs. The intended audience is anybody who is planning on construction work or maintenance work ranging from streets to driveways to roofing. Construction workers as well as do-it-yourself citizens can benefit from this site as it will ease the process of them making a choice as to what route they want to take about an upcoming project they have in mind.