<Li> the Hazardous Materials Transportation Uniform Safety Act (1990) and </Li> <Li> the Hazardous Materials Transportation Authorization Act (1994). </Li> <P> It is estimated that the United States alone makes over 500,000 shipments of hazardous materials every day . More than 90% of these shipments are transported by truck, and anywhere from 5--15% of those trucks are carrying hazardous materials regulated under the HMTA . Approximately 50% of those materials are corrosive or flammable petroleum products, while the remaining shipments represent any of the 2,700 other chemicals considered hazardous in interstate commerce . Accidents that occurred in the transportation of hazardous materials resulted in injury, death, and the destruction of property and the environment . However, the accidents were not limited to the road . The number of incidents regarding hazardous wastes was second in railway accidents behind road accidents . The passage of the HMTA (and its subsequent amendments) has significantly reduced the number of incidents and the gravity of those incidents with hazardous materials in transportation . </P> <P> The HMTA is one of the eight laws defining the EPA's Emergency Management Program . The other laws comprising the Emergency Management Program include the Clean Air Act (CAA), the Clean Water Act (CWA), the Oil Pollution Act (OPA), the Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA), Superfund Amendments and Reauthorization Act (SARA), the Emergency Planning and Community Right - to - Know Act (EPCRA), and the Chemical Safety Information, Site Security and Fuels Regulatory Relief Act (CSISSFRRA). </P>

According to dot what is the most common mode of transportation for hazardous materials