Search Results

Reducing the weight of the M1A2 tank by lightweighting hull, suspension, and track results in 5.1%, 1.3%, and 0.6% tank mass reductions, respectively. The impact of retrofitting with lightweight components is evaluated through primary energy demand (PED), cost, and fuel consumption (FC). Life cycle stages included are preproduction (design, prototype, and testing), material production, part fabrication, and operation. Metrics for lightweight components are expressed as ratios comparing lightweighted and unmodified tanks. Army-defined drive cycles were employed and an FC vs. mass elasticity of 0.55 was used. Depending on the distance traveled, cost to retrofit and operate a tank with a lightweighted hull is 3.5 to 19 times the cost for just operating an unmodified tank over the same distance. PED values for the lightweight hull are 1.1 to 2 times the unmodified tank. Cost and PED ratios decrease with increasing distance.

The problem of accessibility to public transit is well-documented in transportation theory and network literature, and is known as the last mile problem. A lack of first and last mile transit services impairs access to public transit causing commuters to opt for private modes of transit over public modes. This paper analyzes the implications of a shared autonomous vehicle (AV) taxi system providing last mile transit services in terms of environmental, cost, and performance metrics. Conventional public transit options and a hypothetical last-mile shared autonomous vehicle (SAV) system are analyzed for transit between Ann Arbor and Detroit Wayne County Airport for life cycle energy, emissions, total travel time, and travel costs. In the case study, energy savings from using public transit options with AV last mile service were as high as 37% when compared to a personal vehicle option. Energy and greenhouse gas burdens were very sensitive to vehicle powertrain and ridership parameters.

Since 1989, the Northeast Sustainable Energy Association (NESEA) has organized the American Tour de Sol in which a wide variety of participants operate electric vehicles (EVs) and hybrid electric vehicles (HEVs) for several hundred miles under various roadway conditions (e.g., city center and highway). The event offers a unique opportunity to collect on-the-road energy efficiency data for these EVs and HEVs as well as comparable gasoline-fueled conventional vehicles (CVs) that are driven under the same conditions. NESEA and Argonne National Laboratory (ANL) collaborated on collecting and analyzing vehicle efficiency data during the 1998 and 1999 NESEA American Tour de Sols.