In addition, a number of other rideshare software programs have been created to help Americans locate potential carpooling arrangements. Many of these, such as Zimride, CommuteSmart, and RideFinders reach out to university and college students across the United States. Some colleges offer incentives such as discounted parking permits for participants in carpooling programs. Due to green standards set forth by the United States Green Building Council, the LEED standards were created. LEED has six main characteristics: Site Planning, Water Management, Energy Management, Material Use, Indoor Air Quality, and the Innovation & Design Process. There are currently 315 U.S. Universities with at least one LEED certified building and most Green campuses require all new buildings to be at least LEED silver. The LEED project checklist consists of sustainable sites (24 possible points), water efficiency (11 possible points), energy and atmosphere (33 possible points), materials and resources (13 possible points), indoor environmental quality (19 possible points), innovation in design (6 possible points), and regional priority (4 possible points). The point system and rankings for LEED buildings:  Green buildings should primarily focus on key elements of human and environmental health. It would include sustainable site development, water savings, materials selection, and indoor environmental quality. Natural light, recycled and nontoxic materials, climate controls, and eco-friendly cost effective electricity saving resources, are used in green buildings. Additionally, many universities are educating students about green buildings by having a sustainability and the built environment minor/major. Likewise, many universities have green buildings in order to reduce carbon dioxide emissions, water use, and electricity. The three primary goals of green building are to reduce consumption, educate students, and promote sustainable practices. Some ways to reduce consumption, educate students, and promote sustainable practices would be:  Buildings currently account for 1/6th of the world's freshwater use, 1/4th of all wood harvests, 2/5th of all material flows, and 2/5th of all energy flows. By using green buildings, consumption of resources, energy, and/or waste, could be reduced by 50-60%. Some sustainable materials used in Green Building that could reduce that percentage- fly ash, sealtech block, cold-form metal framing, ecosurfaces, reclaimed lumber, composting, waterless urinals, greenscreen PVC-free fabrics, climate upholstery fabrics, evergreen solar panels, dual-flush toilets, and PS400 flat wall form. Duke University has almost 20 buildings that have received a LEED certification and another 10 that are somewhere in the process.