by Bill Cooke
On 20 April, the opening day of the SAE 2009 World Congress, the AVL Technology Leadership Theater presented a forum on “Green Mobility—The Long View”. Organized by Shane Chang at Honda Research Institute USA Inc., the session counted among its panelists:
Professor John Heywood, Sun Jae Professor of Mechanical Engineering and Director of the Sloan Auto Laboratory at MIT. Dr. Heywood recently co-authored a study called “On The Road in 2035—Reducing Petroleum Consumption and GHG Emissions.”
Professor Robert Cervero, Department of City and Regional Planning, University of California-Berkeley. Winner of the 2004 Dale Prize for Excellence in Urban Planning.
Dr. Luca Guala, Systematica. Responsible for designing the transportation system for the Citadel of Masdar.
Professor Sebastian Thrun, Stanford University. Lead the team that won the DARPA Grand Challenge in 2005 for developing a vehicle that could navigate and drive through a desert course without human intervention.
Setting the stage for existing technology
Dr. Heywood opened the session by identifying the three most important goals over the next couple of decades:
Improve our mainstream technologies because “improving our mainstream technologies is what is going to make a difference over the next couple of decades” said Heywood. He also cautioned that “we need to make sure our improvements in technology, especially efficiency improvements, don’t just offset increases in vehicle performance and size but genuinely reduce fuel consumption.”
Conserve energy by changing consumer behaviors “because it reduces the size of the problem and that is extremely important.”
Transform our energy supply base to low CO2 fuels because “eventually our environmental damage [needs to be] brought under control but my concern is that is all we talk about,” Heywood advised—and transformational changes take decades, not years, to implement.
“We are all stampeding towards an electric vehicle future. I’m not against that and we should be exploring it but there are a lot of challenges—the primary one being the cost of these vehicles and there are infrastructure issues as well,” cautioned Heywood.
Even without the operational issues there is still the matter of scale. For example, President Obama has issued the United States the challenge of having one million plug-in hybrids on the road by the end of 2015—a goal which many keynote speakers supported but also identified significant barriers to achieving. During the intervening six and half years in the US alone, the auto industry will sell a projected 70-80 million internal combustion engine cars, pointing out the importance of improving today’s technology.
Corporate Average Fuel Efficiency (CAFE) challenge
Not that the intervening six and a half years will be easy to achieve. In regards to the improved CAFE standards included in the Energy Independence and Security Act of 2007 (EISA 2007), Dr. Heywood states:
If you ask people outside of the industry, they will say it is no big deal, if the industry gets off its duff it will do it but those of us who are inside of the industry and knowledgeable about the challenges believe that this is a more rapid set of changes in a decade than the industry has ever attempted before.
Here are some examples of actions that would be required to achieve the target of at least 35 mpg specified by EISA 2007: [Note: NHTSA has released CAFE standards for MY 2011, but is engaging in further consideration and analysis prior to issuing rules for subsequent model years. (Earlier post.)]
|CAFE mpg US (cars / trucks)||27.5 / 22.2||35.7 / 28.6||≥35 / ≥35|
|CAFE (L/100km) (cars / trucks)||8.6 / 10.6||6.6 / 8.2||≤6.7 / ≤6.7|
|Weight||X||0.9 - 0.95X||0.8 - 0.85X|
|Advanced powertrain (%)||40||60|
Examples of advanced powertrains are turbo charged gas engines, diesel and hybrid. Prof. Heywood points out that for an average vehicle a “20% reduction in weight = 825 lbs. [374 kg]”
Longer Term Green House Gas emissions reductions
“Everything I can think of, everything you can think of, everything anyone can think of, will be needed to get down to” an 85% reduction in greenhouse gases emissions by 2050, said Heywood. We will have to make significant improvements to all elements of the equations.
Dr. Heywood believes it will take a collection of actions: to get to a future state with 25% of today’s level would require six equal elements with a 20% improvement (0.8)6. “We are going to need to find major areas where we are going to be able to achieve major reductions in emissions and they will not all be technology.” Five possible areas of improvements include: reducing miles driven; increasing the number of people per trip; reducing the number of trips; improving the vehicle efficiency; and improving the efficiency of the fuel supply.
Urban planning as part of the solution
Dr. Robert Cervero, Professor in the Department of City and Regional Planning at the University of California Berkeley, shares Dr. Heywood’s view that it will take more than vehicle technology to develop sustainable transportation and believes urban planning needs to play a significant role. “More Americans live in cities than outside of cities. Cities account for 2% of the world’s area and yet they account for 75% of the resources and 75% of the waste,” said Cervero.
Prof. Cervero believes that several things need to change, there are “going to be changes values and lifestyle preferences as we become more mindful of our environmental footprint and gives rise to different settlement patterns and different urban forms.”
Prof. Cervero doesn’t expect life to become simpler; he believes changing demographics due to more non-traditional households, seniors remaining active later into life, and more fragmented careers “lead to a much more complex, diverse, kind of travel both spatially and temporally which is going to increase the demand for auto mobility...the ability to go to different places, for different purposes at different times.”
Still, Prof. Cervero believes that VMT (vehicle miles traveled—the number of miles you drive in your car each year), needs to decrease to have a more sustainable environment and he believes Transit Oriented Development (TOD) is a way to achieve this goal in a way that people can embrace.
One of the keys to TOD is to desegregate commercial and residential land use so people live near where they work and even if they have to commute to work the distributed nature housing and commercial avoids the overcrowding in one direction you experience with dedicated residential neighborhoods.
TOD is about “advancing the right kind of a balanced model. A mix of technology, a mix of urban planning, really setting the stage so people can make intelligent, resourceful decisions on when to use certain modes of transportation,” said Cervero.
Prof. Cervero believes Stockholm, Sweden and Curitiba, Brazil are two good examples of the TOD principle. “Stockholm is one of the few cities globally where VMT has declined. It is partly due to building a city where for certain trips public transport is a much more viable alternative.”
He calls Stockholm’s neighborhoods a “string of pearls” with a balanced use of land for work and housing—and yet Stockholm has relatively high level of car ownership (555 cars/ 1000 inhabitants). Most of the people “use public transportation for the daily grind” while they use their cars for shopping and weekend trips.
Quality urban planning isn’t limited to wealthy cities in Western Europe. Curitiba’s transportation system “is not extensive but it is very viable,” said Cervero. He added that it is a mixed use system with “linear corridors serviced by articulated buses powered by natural gas. Some of the most expensive real estate in the city is along the corridors” but people still own cars for side trips. Prof. Cervero compares Curitiba to Brasilia which is a city of comparable wealth. Brasilia is the nation’s capital and represents urban planning circa 1960 with wide car-friendly boulevards but little public transportation.
|Cars (vehicles/1000 people)||238||253|
|Public transit (trips/year)||355||97|
|Vehicle Kilometers Traveled (km/year per vehicle)||7,900||16,700|
Prof Cervero acknowledges “that it is easier to get the pollution, rather than the people, out of the car” and is a big supporter of car sharing. Car sharing is a process where people rent cars to fulfill certain tasks: they may rent a small car for a couple of hours to go shopping and a larger car for a week long trip. He believes “monolithic vehicle design”—where people buy one car to fit all of their needs—is outdated.
Masdar: “tabula rasa” in Abu Dhabi
|The first Masdar PRTs. Click to enlarge.|
The supporters of Masdar believe the entire nature of vehicular travel is outdated and Dr. Luca Guala has the once-in-a-lifetime opportunity to create a transportation network from scratch. He works for Systematica, who has been contracted to design the Personal Rapid Transit (PRT) system for Masdar city.
Masdar is a multi-billion dollar project to create a mile-square city in a desert environment where “nothing grows” today. The goal is to design a city that “is completely sustainable, to be completely self sufficient, to be able to live on its own produced energy from the sun, the wind, of processing its own waste” according to Guala.
The city will have two transit levels. The upper level will be for pedestrians and light weight vehicles like bicycles, Segways and electric bicycles. The lower level will be populated with PRTs. Cars will be prevented from entering the city. Dr. Guala points out that “People are not a blank sheet, they have their own views, their own preferences” and while some change in human behavior is expected, he realizes in the end his customers needs have to be addressed and the inhabitants need to embrace sustainable behaviors.
The PRT as an automated taxi that is 4m long by 1.4m wide and can hold four people and "if you don't mind squeezing a bit, up to six people.” The first wave of vehicles will be built by a Dutch firm 2getthere and will have a range of 60 km which should be good for several hours of use. The top speed will be limited to 40 km/h (25 mph) but Dr. Guala points out that “the longest trip will not take more than 5-6 minutes” due to the city’s small size.
The vehicles will be controlled centrally and the computer will match supply to demand and provide routing instructions. Each trip will have the option of following several different possible routes but the PRTs will be following pre-established paths.
PRTs have several advantages over traditional mass transit “which even in a good quality system you may only attract 10% of the people” according to Guala. With a PRT you won’t be riding with strangers, wait times are expected to be 3 minutes or less, you won’t have any intermediate stops or transfers and you’ll end up within 50-150m of your final destination.
Advantages over a traditional car include a higher utilization rate and Dr. Guala is expecting “one PRT can do the job of forty cars.” Other advantages include never needing to park and no ownership responsibilities.
|A Q&A with Luca Guala on the Masdar PRT is available here.|
PRT advantages over a human driven taxi include freedom from accidents caused by human error with PRTs offering “a rail level of safety” according to Dr. Guala. Other advantages include compliance to a master dispatcher and eliminating the drivers’ compensation, weight and space.
PRT challenges include the reliance on a central computer, the inability to adapt the vehicle to your personality via ownership and losing the local color and insight provided by a cab driver. Another issue is being capacity constrained during rush hour if you only have one person per vehicle. Masdar plans to experiment with various car pooling strategies called “group rapid transit” that will give you a financial incentive to share PRTs during peak times.
“Exclusive right of way means the PRT cannot mix with other traffic” according to Guala, which is another PRT challenge outside of Masdar.
Can this experiment be replicated in existing cities? Yes it can, Masdar is a blank sheet project...but PRT can be built in an existing city. It will probably have to travel elevated...but the elevated infrastructure will not be as intrusive (as systems today), because the total vehicle weight loaded is 1,500 kg.—Luca Guala
For reference, the fully loaded PRT is approximately 80% the weight of 2009 VW Rabbit.
Dr. Guala is expecting a long roll out for PRTs. The city’s first section, MIST - Masdar Institute of Science and Technology, will be complete by the end of 2009. Heathrow airport is slated to have PRTs installed at a similar time. Cities like Ithaca New York have expressed interest and Masdar itself isn’t slated to be fully operational until 2015.
Guala believes it will take time for the technology to be implemented on a large scale. He predicts it will be “10-15 years before large applications will built...we want to see the success of small applications.”
Although he is an advocate for PRTs, “it is a new animal in the concrete jungle”. He doesn’t see them as a panacea and he expects that they “will be a complement to cars and mass transit”, not a replacement.
Improving the efficiency of vehicular travel
For those of us confined to the existing infrastructure of roads, Prof. Sebastian Thrun believes robotics can complement and eventually eliminate the chore of driving and “make driving and transportation significantly more efficient”.
Dr. Thrun pointed out several flaws with today’s system. On average we spend 1.25 hours/day commuting; the blind, elderly and children “are excluded from the driving experience and need to be chauffeured around”; and at highway speeds we use only 8% of a highways surface, leaving 92% open as buffer space. We need so much buffer space “because, by and large, we are lousy drivers” said Thrun.
“If we can augment the human drivers with robots we might be able to squeeze the cars into 16% spacing leaving 84% free” said Thrun, which effectively doubles our highway capacity.
Convoys of automatically controlled vehicles is another way to improve efficiency. By reducing the gap between vehicles to take advantage of drafting, similar to NASCAR racers, Thrun points out that we “can reduce our energy usage by 11-17%”.
Our imperfections at driving may be an annoyance when it comes to traffic congestion but it is more serious when we look at traffic fatalities. Dr. Thrun reminded the audience that more than 42,000 Americans are killed each year in auto accidents and 2.7 million are injured. Auto accidents are also the leading cause of death for people between 3-33 years old.
In perhaps the most sobering statistic shared at the 2009 SAE conference, Prof Thrun’s investigations have led him to believe that 1-1.2 million people are killed annually in traffic accidents throughout the world, primarily in the developing nations. “If you were to invent something today, and the human death toll would be of this magnitude, we would never get approval to do it,” said Thrun.
Automated driving won’t take these numbers to zero but even an improvement of a couple percent could result in hundreds if not thousands of lives saved per year.
Like Prof Cervero, Prof. Thrun is an advocate of car sharing. “In the future, there might be entirely new modes of car sharing. I might be able to pull out my phone, push a button and a car comes up to me...I wish to think of driving as a commodity where car ownership is secondary to the needs of transportation, where we can choose our vehicles based upon our needs," said Thrun.
He projects that by “2040 one-half of all miles will be driven automatically” enabling us to have safer, more productive, more sustainable lives. He draws parallels to the development of air travel. “It was 30 years from Lindberg’s flight across the Atlantic to more than 50% of all trans-Atlantic travel occurring in airplanes.”
Perhaps we are on the cusp of a new age in ground travel.
Bandivadekar, A., Bodek, K., Cheah, L., Evans, C., Groode, T., Heywood, J., Kasseris, E., Kromer, M., Weiss, M., “On the Road in 2035: Reducing Transportation’s Petroleum Consumption ans GHG Emissions,” MIT Laboratory for Energy and the Environment, Report No. LFEE 2008-05 RP, July 2008
R. Cervero, Transit-Oriented Corridors, sidebar in The Transportation/Land Use Connection, T. Moore, P. Thornes, B. Appleyard, Planning Advisory Service Report Number 546/547, 2007, pp. 136-137
R. Cervero, The Transit Metropolis. Washington, D.C.: Island Press, 1998; translated into Chinese, China Architecture and Building Press, 2007
R. Cervero, The Scandinavian Model: Strings of TODs, Urban Land, May, 2004, p. 76.