conference paper
conference paper
Information is effectively the same as a change in uncertainty, and therefore, they share the same unit system of measurement, such as bit, nat, and qubit. This paper adopts a strict definition of information and implements a method to quantify traveler information provision using an information-based modeling framework developed in earlier research. The framework combines a cognitive grouping model and information update scheme (learning) for calculating in quantified units the amount of information any traveler has about a route, which can be further decomposed to any sub-route during any time period of relevance. Such numerical quantification can be meaningful in evaluating network performance enhancement schemes such as ATIS and in modeling decision making when uncertainty is a significant factor. An application study with traffic network and detector data near downtown Los Angeles is used to demonstrated the use of the method for quantifying information provision from a dynamic message board, as an illustrative case. Further improvement and research directions are identified.
conference paper
policy brief
Tractor-trailers dominate the truck cargo industry. Between 1990 and 2010, this industry grew significantly; vehicle miles traveled increased 87 percent and ton-miles increased by 47 percent. While the growth of trucking miles and tonmiles is a positive indicator of economic transformation and expansion, the trucking sector also produces negative externalities, including but not limited to pavement damage. Pavement damage is closely tied to vehicle weight, which is a product of private market decisions driven by the cost of delivery per ton and the frequency of delivery. Understanding the interplay between fuel cost and private sector decisions on truck dispatch (i.e., frequency and load of trucks) is key to understanding infrastructure damage.
policy brief |
Aug 2020
research report |
Jun 2017
MS Thesis
California’s transportation and power generation sectors emit more than 50 percent of the state’s greenhouse gas (GHG) emissions. The state GHG emission mitigation goals include reducing GHG emissions to 1990 levels by 2020. Additionally, to improve air quality throughout the state, aggressive criteria pollutant emission standards have been established for both sectors. Transitioning from fossil fuels to renewable fuels is one strategy to meet these environmental goals. Landfills and wastewater treatment plants are a source for the production of alternative fuels like renewable natural gas (RNG) and hydrogen (H2) which could then be used in either sector. To evaluate this strategy, the impact on GHG and criteria pollutant emissions, and on air quality resulting from the production and use of RNG in zero or near-zero emission medium-duty vehicles (MDV) and heavy-duty vehicles (HDV) are analyzed. The research reveals that (1) RNG produced from biogas is the most cost effective strategy to utilize the limited resource of biogas available in California even though H2 is the most attractive fuel, (2) the transportation sector is the more effective sector for the use of RNG fuel, (3) MDV and HDV outfitted with commercially available near-zero emission CNG engines with RNG results in substantial reductions in both GHG and criteria pollutant emissions, and significantly improves air quality than the use of H2 in LDV, and (4) the reductions in GHG and criteria pollutant emissions and improvements in air quality exceed those achieved with the MDV and HDV populations envisioned by the State Implementation Plan (SIP)
book/book chapter
Transportation policy making often requires evaluating a proposed discrete change, whether it be a physical investment or a new set of operating rules. Some proposals, like the rail tunnel under the English channel, are one-time capital investments with long-lasting effects. Others, like congestion pricing proposed for The Netherlands, require major behavioral and political groundwork.
working paper |
Oct 1993
working paper |
Jan 1997
working paper |
Sep 1995
working paper |
Sep 1994
working paper |
Jul 1997
published journal article
The primary intent of this paper is to explore the claim that transportation benefits can be derived from neotraditional neighborhood design. Conventional transportation planning models are used as tools to evaluate the performance differences of two hypothetical street networks designed to replicate a neotraditional and a conventional suburban community. Relative transportation benefits are measured in terms of vehicle-miles traveled, average trip lengths, and congestion on links and at intersections. This comparison provides an assessment of how well the two networks in question deal with trips generated by the activities which they serve. All aspects of the modeled communities are held constant except for the actual configuration of the networks. The results of this evaluation indicate that equivalent levels of activity (defined by the land uses within the community) can produce greater congestion with conventional network structures and that corresponding average trip lengths are generally longer. The ultimate goal is to determine if one network type, because of the nature of its design, can result in a more efficient transportation system. The results indicate that neotraditional designs can improve system performance.
research report
Charging-as-a-Service (CaaS) is an innovative electric vehicle (EV) charging station model that allows customers access to EV chargers through a contract with a provider responsible for design, deployment, operations, and maintenance. Little is known about the motivations and experiences of stakeholders involved in CaaS operations, including providers, electric utilities, and customers. A grey literature review identified CaaS services, provider-described benefits, and utility-provided CaaS and charging services. Then, we conducted semi-structured interviews with 13 stakeholders to identify critical themes on interactions between stakeholders and the perceptions, challenges, and opportunities of the CaaS business model in addressing charging station needs in California. CaaS may have structural benefits to customer-owned chargers and could improve charger reliability, provide scalable solutions, and reduce customer fatigue with EV charging deployment. However, CaaS faces the same challenges present in the broader charging industry. The findings in this study can guide policymakers in supporting maintenance-related workforce development and streamlining and crafting EV charging infrastructure-informed subsidy programs. Additionally, stakeholders recommend municipal-led EV infrastructure planning and funding for chargers in disadvantaged communities. These interviews clarify the role of CaaS within the EV charging industry and confirm the need for engaged policymaker support to clear roadblocks, support investment, and educate customers about decision-making, which benefits all EV charging stakeholders.
working paper
conference paper