WASTE MATERIALS IN HIGHWAY CONSTRUCTION: LESSONS FROM NEW YORK STATE

The New York State Department of Transportation's (NYSDOT's) use of waste materials in highway construction has been influenced by state and federal legislation. The department's current policy on recycling includes use of waste materials of good quality and uniformity that perform satisfactorily and are cost-effective. Waste materials that conform to this policy are usually listed as options in the NYSDOT Standard Specifications. The policy allows designers and contractors to find the least expensive way to build a highway of good quality while reusing materials as warranted by the department. This article reviews NYSDOT experience with recycled portland cement concrete as aggregate, reclaimed asphalt pavement, fly ash, cullet (waste glass), and scrap tires. In conclusion, it is pointed out that, with landfill space at a premium and pressure to recycle increasing, New York must continue to take a hard look at using recycled materials in highway construction, and search for answers to such difficult questions as: How may NYSDOT make better use of materials--such as rubber and fly ash--that still elude state recycling efforts? and, Should highways constructed of recycled materials be treated as landfills under solid-waste management laws, with all the effort and expense that entails?