The introduction of particulate and oxides of nitrogen (NOx) after-treatment controls on heavy-duty vehicles has spurred the need for fleet emissions data to monitor their reliability and effectiveness. The University of Denver has developed a new method for rapidly measuring heavy-duty vehicles for gaseous and particulate fuel specific emissions. The method was recently used to collect 3088 measurements at a Port of Los Angeles location and a weigh station on I-5 in northern California. The weigh station NOx emissions for 2014 models are 73% lower than 2010 models (3.8 vs 13.9 gNOx/kg of fuel) and look to continue to decrease with newer models. The Port site has a heavy-duty fleet that has been entirely equipped with diesel particulate filters since 2010. Total particulate mass and black carbon measurements showed that only 3% of the Port vehicles measured exceed expected emission limits with mean gPM/kg of fuel emissions of 0.031 ± 0.007 and mean gBC/kg of fuel emissions of 0.020 ± 0.003. Mean particulate emissions were higher for the older weigh station fleet but 2011 and newer trucks gPM/kg of fuel emissions were nevertheless more than a factor of 30 lower than the means for pre-DPF (2007 and older) model years.

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The application of the concept of sustainability by transportation agencies is often limited by agencies' understanding of what sustainability means and how it can be integrated into the regular functions of the agencies. This paper presents a flexible approach and framework that can equip transportation agencies with the tools required to understand what sustainability means and incorporate sustainability into the organizational culture. This approach and method can also help agencies lay the groundwork for the use of performance measures so the agencies can progress toward sustainability goals and outcomes. The framework development process was an extension of findings from literature review, case studies, and interviews conducted as part of ongoing research under the NCHRP project Sustainability Performance Measures for State Departments of Transportation and Other Transportation Agencies. The proposed framework can be applied or adapted for use in a range of transportation agencies, including state departments of transportation and metropolitan planning organizations. A key feature of this framework is that it moves away from the traditional sustainable transportation perspective and instead promotes the consideration of transportation from a holistic sustainable development perspective. The framework defines broadly applicable transportation goals that can be broken down into a menu of objectives and performance measures to cover various transportation contexts. The framework is also designed to direct an agency's strategic planning toward the practical implementation of sustainability through performance measurement

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