Ben is interested in advanced technologies for heavy-duty vehicles. Many of these progressive technologies offer potential fuel savings and emissions reductions--two issues of great significance in increasingly stringent regulatory environments such as California. While trucks powered by natural gas and other alternative fuels are proving to be an effective substitute for heavy-duty vehicles such as buses and refuse trucks, hybridized trucks, which supplement diesel power with another energy source, are also emerging as a technology that has the potential to make a significant contribution to curbing diesel consumption and lessening the environmental footprint of on-road heavy-duty vehicles. Ben's aim is to study the commercial viability of such heavy-duty hybrids.