Technology & Innovation

Going the Extra Mile: Intelligent Energy Management of Plug-In Hybrid Electric Vehicles

Kanok Boriboonsomsin, Guoyuan Wu, and Matthew Barth

Plug-in hybrid electric vehicles (PHEVs) have generated significant interest for their potential to decrease dependence on imported oil and to cut pollution and greenhouse gas emissions. While hybrid electric vehicles (HEVs) rely on their internal combustion engines to recharge their batteries, PHEVs generally have larger batteries and can be recharged by plugging into an outside electricity source, such as a standard home outlet (Figure 1). As a result, PHEVs are potentially more efficient and cleaner than HEVs, in part because more of their energy can come from clean, renewable sources.

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Quantified Traveler: Travel Feedback Meets the Cloud to Change Behavior

Raja Sengupta and Joan L. Walker

Halting climate change will require a concerted effort to reduce emissions from on-road vehicles. While significant progress has been made to improve vehicle efficiency and reduce CO2 emissions, surface transportation accounted for half the increase in US greenhouse gas (GHG) emissions over the past two decades. Today, surface transportation accounts for 24 percent of all US emissions. Automobile improvements alone will not be sufficient to meet federal and state emissions targets; policy makers also need to identify solutions that reduce the demand for car travel. Information technology offers a promising breakthrough on this front.

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Can We Have Sustainable Transportation without Making People Drive Less or Giving up Suburban Living?

Mark Delucchi

City planners, transportation analysts, and policymakers have struggled to reconcile the promises and problems created by suburban land use and automobiles. On the one hand, automobile use and suburban living are widely and highly valued; as people become wealthier, they tend to buy cars and live in bigger homes farther away from central cities. Many urban planners, however, blame automobiles and automobile-driven sprawl for a wide range of problems, including climate change, road fatalities and injuries, rising traffic congestion, ugly urban form, oil dependency, and increasing social fragmentation. Most approaches to these problems focus on curtailing automobile use and its impacts. Outside of densely populated cities, however, it is hard to reduce personal automobile use.

An Innovative Path to Sustainable Transportation

Daniel Sperling

Contrary to popular belief, the world is awash in fossil energy, much of which can be readily converted into fuels for our cars, trucks, and planes. We are not running out of fossil fuels. The abundance of fossil fuels means we are unlikely to see high fuel prices due to scarcity. Indeed, most analysts predict that future oil prices will not be much higher than today’s, apart from occasional peaks due, for example, to conflicts in the Middle East. Prices might even end up lower as new exploration and extraction technologies for shale oil, heavy oils, deep-sea oil, and oil sands make it cheaper and easier to extract fossil energy. Thus, we cannot depend on high oil prices to reduce transport energy use and greenhouse gas (GHG) emissions.

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2017-05-26T21:41:39+00:00Categories: ACCESS 45, Fall 2014|Tags: , |

THE ACCESS ALMANAC: Vehicular ad hoc Networks: Storms on the Horizon

Amelia Regan

Researchers and policy makers have long anticipated fully connected vehicular networks that will help prevent accidents, facilitate eco-friendly driving, and provide more accurate real-time traffic information. Today, vehicular ad hoc networks (VANETs) offer a promising way to achieve this goal. Using advances in wireless communications, computing, and vehicular technologies, VANETs rely on real-time communication not only with roadside sensors but also among vehicles and pedestrians. While there are still communication problems to solve within these complex systems, concerns about privacy, liability, and security are the chief obstacles that prevent progress towards large-scale implementation. Download the PDF.

Dynamic Ridesharing

Elizabeth Deakin, Karen Trapenberg Frick, and Kevin Shively

Most cars can carry at least four passengers, but the average auto occupancy rate for all trips in the US is only 1.6 persons. Because all the empty seats in cars represent our greatest source of untapped transportation capacity, promoting ridesharing is of considerable interest. Government agencies across the country employ ridesharing programs both to provide transportation at low cost and to reduce traffic congestion and the other costs of solo driving.

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2018-02-13T23:21:19+00:00Categories: ACCESS 40, Spring 2012|Tags: , |

THE ACCESS ALMANAC: Solar Parking Requirements

Donald Shoup

Solar panels have begun to find a new place in the sun—on parking lots surrounding commercial and industrial buildings, mounted on canopies providing shade for the parked cars. Parking lots in asphalt-rich cities have great solar potential because the panels can be oriented to maximize power production during summer afternoons when electricity is most valuable. Solar-powered parking lots can mitigate the substantial increase in peak-hour energy demand that major developments create, but few developers now install solar canopies over their parking lots. Although the demand for electricity peaks on days when the sun shines brightest, solar power accounts for less than 1 percent of our total electricity supply.

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2018-02-13T23:37:18+00:00Categories: ACCESS 40, Spring 2012|Tags: , |

Introduction: Transportation Technologies for the 21st Century

Elizabeth Deakin

New technologies are transforming the way we plan, design, build, and operate transportation systems. Transport agencies use them to count traffic, detect crashes, collect tolls and fares, and manage transit operations and traffic signal systems. Travelers depend on traffic condition reports, electronic maps, on-board vehicle performance monitors, real-time transit arrival information, and a host of other services that did not exist a generation ago. Some of us are already driving hybrid vehicles or commuting in buses powered by hydrogen or biofuels. For the future, we all are counting on additional advances in transportation technology, not just to get us where we want to go, but also to reduce greenhouse gases, improve air quality, and support economic development.

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Saving Fuel, Reducing Emissions: Making Plug-In Hybrid Electric Vehicles Cost Effective

Daniel Kammen, Samuel Arons, Derek Lemoine, and Holmes Hummel

Cars and light trucks in the U.S. consume about eight million barrels of gasoline per day, more than total US petroleum production. They account for eighteen percent of national greenhouse gas emissions. Both motor vehicle gasoline consumption and emissions have been rising at about 1.5 percent per year. Plug-in hybrid electric vehicles (PHEVs) could alter these trends. On a vehicle technology spectrum that stretches from fossil-fuel- powered conventional vehicles through hybrid electric vehicles to all-electric vehicles, PHEVs fall between hybrids and all-electrics. They have both gas tanks and batteries, like hybrids, and can run either in gasoline-fueled mode or in electric mode. Their batteries are much larger than batteries in other hybrids, and they can store electricity directly from the grid as well as electricity derived from regenerative braking, as do conventional hybrid vehicles. PHEVs combine the best aspects of conventional vehicles (long range and easy refueling) with the best attributes of all-electric vehicles (low tailpipe emissions and reduced petroleum use). Widespread use of PHEVs could reduce transportation-related GHG emissions, improve urban air quality, reduce petroleum consumption, and expand competition in the transportation fuels sector. Several companies now offer to convert hybrid vehicles to PHEVs, and several automakers have announced PHEV development projects.

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2018-02-07T23:15:19+00:00Categories: ACCESS 34, Spring 2009|Tags: , |

Intelligent Transport Systems: Linking Technology and Transport Policy to Help Steer the Future

Elizabeth Deakin, Karen Trapenberg Frick, and Alexander Skabardonis

If you’ve seen an electronic message sign along the highway that tells you how long it will take to get downtown or to the airport, or paid your toll or your parking fees with an electronic tag, or ridden a bus that triggered the traffic lights to turn green as it approached them, then you have experienced some of the benefits of Intelligent Transportation Systems (ITS)—an umbrella term for a variety of new technologies and operations methods for highways and transit. Other on-the-ground ITS applications are less visible to the average traveler, but every bit as useful: they help traffic managers detect and respond to accidents promptly, handle the extra traffic that special events generate, and help state workers safely plow snow on mountain roads in blinding snowstorms.

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2018-02-07T23:30:02+00:00Categories: ACCESS 34, Spring 2009|Tags: |