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Meeting Future Transportation NeedsThe Surface Transportation ChallengeGrowing urban vehicle
congestion, emissions pollution and vehicle fuel economy are related personal
transportation issues that various Administrations have sought to address for
decades. Measures taken have included CAFÉ standards (Corporate Average Fuel
Economy), higher federal and local excise taxes on gasoline, subsidies for
alternative fuel vehicles, and even taxes on luxury cars. Nevertheless, vehicle
congestion continues to grow through The Clinton Administration
focused on fuel economy and emissions, most notably in their public/private
venture with the Big Three automakers to produce a New Generation of Vehicles (PNGV)
capable of 80 miles per gallon of gasoline. However, well before such a vehicle
could be produced in On ·
Aim at longer range goals [than the PNGV initiative]
with greater emphasis on highway vehicle contributions to energy and
environmental concerns; ·
Move to more fundamental R&D at the component and
subsystem level; ·
Assure coverage of all light vehicle platforms; ·
Maintain some effort on nearer term technologies that
offer early opportunities to save petroleum; and ·
Strengthen efforts on technologies applicable to both
fuel cells and hybrid approaches; e.g., batteries, electronics, and motors. Blueprint for a New Surface Transport InfrastructureMultiples of current roadway
capacity will be needed to keep traffic flowing smoothly, not only on highways
but also on city thoroughfares. The Transportation Research Board produced a
report in 1974 that gave substantial coverage to congestion alleviating
“dual-mode” vehicles able to platoon on guideways, but also drive like
normal cars. Developments during the 1990's suggest the outlines of a
progressive evolution towards multi-mode vehicles with: 1.
Ordinary car mode 2.
Platoon mode 3.
Driverless mode 4.
Guideway mode A brief look at each of the latter three modes will help define the best approach to building an effective new surface transportation infrastructure. This blueprint is evolving along with transportation technologies around the world. Platoon ModeThe only way to increase road capacity without building additional lanes is to decrease the following distances between cars using electronic, and possibly mechanical, coupling. Of value at traffic bottlenecks, this capability would allow many cars to accelerate or brake simultaneously. Instead of waiting after a light changes to green for drivers ahead to react, a synchronized platoon would move as one, allowing an increase in lane throughput of up to 3-5X. Implemented first on major congested thoroughfares, platoons will require priority lanes and electronic signaling, and intersections outfitted to provide automatic warning of dangerous conditions (such as cars running red lights), but not major roadway reconstruction. Drivers would need a special license endorsement on account of the new skills required and the added responsibility when driving in the lead, but platoons would offer substantially shorter commutes during peak periods, the main incentive for purchasing platoon capabilities in a new vehicle, or possibly retrofitting existing ones. A secondary benefit is that on longer highway trips, vehicles could be mostly unattended while in following mode.
Driverless Mode
Automatically driven vehicles can
already operate under certain constraints. Driverless
vehicles that can autonomously join/leave platoons and safely park in designated
“taxi-stands” would be able to offer service to non-drivers on major routes,
at a cost comparable to bus service. The
capability will inevitably progress to door-to-door service, particularly useful
for the elderly, children and package delivery.
Guideway ModeLong platoons can travel very safely
at high speeds on guideways that eliminate surface interference. Such guideways
could carry 10,000 vehicles/hour at the current speed limit, five times more
than a highway lane, and more at higher speeds. Elevated guideways would first
be placed next to major thoroughfares and railways in congested areas.
Both higher speeds and fuel efficiency can be achieved due to the much
lower aerodynamic drag possible with platoons. On-demand and door-to-door travel
at an average speed of 100MPH would be faster than air travel for trips of at
least 300 miles, and vastly more convenient. Once built nationwide, the marginal
costs would be low and at least 1/3 of airport traffic, all buses and Amtrak
would be eliminated. Maglev remains unproven but is much
more likely to be economically viable for individual vehicles than for station
trains because of up to 100X greater utilization of the expensive track. In the
open air, speeds would still be limited to approximately 200-300 MPH, but
marginal energy use and operating costs could beat domestic air on any overland
route. Maglev sleepers could go coast-to-coast in 10-15 hours, and they would
really be a great way to “see the country”. Whether magnetic levitation or
wheels are used, guideways would supply propulsive power, eliminating the need
for vehicles to carry large energy stores and the means of converting them.
Guideways address safety, capacity of the available rights-of-way, speed and
propulsion whereas fuel cells and PNGV address only the last. While private concerns will construct the new generation of vehicles, and might even capitalize the infrastructure, the Federal government’s role is to create the opportunity. Stages two and three can be attained with legislative help but relatively little public money. Congress should fund R&D with the ability to deliver technical standards for roadways and vehicles; and create model laws for the states to re-regulate liability and license drivers. Stage 4 guideways, especially Maglev, will require very large infrastructure expenditures that will cost the nation on the order of one trillion dollars.[1]
Conclusion
The federal government and private industry need to take a more imaginative approach to building American surface transportation infrastructure for the 21st century. Current “mass transit” approaches are woefully inadequate, both because they ignore the average citizens daily dependence on a personal transportation vehicle and the new technologies that could sharply decrease congestion related delays. Public and private attention is focused only on enhanced fuel economies, fuel-cells and limiting air-borne pollution. What is missing—and solely needed—are joint public/private R&D efforts that advance efforts to take advantage of the electronics revolution. If the surface transportation infrastructure outlined above is properly developed, future Americans could join ad hoc “trains” that form and disperse on an as-needed basis as people “drive” to work, travel to another city, or go on long-distance vacations. [1]
Elevated
guideway costs for one prototype (www.ruf.dk) are estimated at about $7
million per route mile in
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