Dualmode Debate Page
The purpose of this page is to encourage people to offer their thoughts as to the strengths and weaknesses of dualmode transportation concepts. Contributions are welcome and should be addressed to Jerry Schneider. If judged to be appropriate, they will be posted for everyone to see.
A dualmode transportation system is defined as one that provides for travel on both the conventional street/highway system as well as on exclusive guideways under the control of a computer system (i.e. fully automated, hands-off operation). The basic idea is that such a system would make possible a transition from current conventional auto-dominated systems to a more effective system that adds a high speed, high capacity network for longer trips within and between large, often highly congested, urban areas.
For an overview paper, see Dualmode, the Transportation of the Future, by Francis D. Reynolds. Also see a more recent paper by Reynolds that was published originally in The Futurist magazine, September-October, 2001. Also see the e-book which is the most up-to-date (2006) description by Reynolds, entitled The Revolutionary Dualmode Transportation System. It has 22 Chapters.
The Danish RUF system is currently the leading and most extensively developed example of such a dualmode system, in Europe.
The American MegaRail system has built a prototype guideway segment and vehicle. MegaRail is concentrating development on manually-controlled mass transit and commuter rail trains, but these trains will also incorporate a manually-controlled dualmode tram that consists of short dualmode trains that can leave the guideway and provide BRT type service to locations away from the guideway. This capability will be demonstrated in the full-scale, fully-operational production prototype slated for completion near the end of 2005. This dualmode tram will be both street and guideway capable and may well be the first real dualmode system to be demonstrated. A prototype vehicle was undergoing initial testing in late 2009.
Persons unfamiliar with the dualmode concept are urged to review the RUF web pages, particularly the Frequently Asked Questions section, to gain an understanding the concepts involved. A checklist of dualmode issues is also available via the Table of Contents of the Proceedings of a national conference on dualmode transportation. Web pages on all other currently known dualmode concepts are available on a dualmode quicklinks page.
Contributions ( in chronological order)
System Design Parameters for Replacing the Private Automobile, by Jon Bogle, 1/12
New book: The Third Generation Roadway: Metropolitan Transport for the 21st Century, by Roger Davidheiser - quite inspirational, good graphics, paperback, 287 pp., 4/2011 - describes a visionary dualmode concept and includes an assessment of the concept. Information about the content of the book is available here.
Information about a new dualmode concept called DAVe (Dual-mode Autonomous Vehicles), by William Alden, 9/10
Link to a new General Transport System Foundation brochure, located in Sweden. It's concept involves both PRT and dualmode capabilities for both freight and passengers, 9/10
Abstract of SolaTrek dualmode concept presentation in Las Vegas, by Frank Randak, 5/10 (see http://www.solatrek.com for more details)
Blog that is focused on a dualmode concept that describes ITS-Park for smart cars that can park themselves, by Jim Haugen, 11/09
Dual Mode Vehicle and Infrastructure Alternatives Anaysis, by Christine Ehlig-Economides and Jim Longbottom, 136 pp, (4/08)
An Interface Standard for a General Transport System, by Bengt Gustafsson, (12/07)
Collaboration among Mutually Dependent Players is Required to Achieve Large Scale Change in a Ground Transportation System, by Jim Longbottom, (6/07)
Customer Response to Dual Mode Personal Rapid Transit, by Yonas Jongkind, (6/07), MBA Thesis, 74 pp
The Revolutionary Dualmode Transportation System, by Francis D. Reynolds, (7/06), e-book, 22 chapters
Envisioning a Desirable Personal Transport System for the Future, by larens imanyuel, (7/11/06)
Trade-offs to consider when designing a transit system, by J. Edward Anderson, (11/10/2005)
Information about the content of the Virtual Workshop on Dualmode Transportation, by J. Schneider, (9/16/05)
Links to three excellent illustrated updates from RUF International: One deals with guideways, another deals with how fuel cells could be used in RUF vehicles and the third deals with implementation strategy, by Palle Jensen, (9/16/05)
On finding niches for a dualmode transportation system in a large U.S. metropolis, by J. Schneider, (9/12/05)
Comments on the LeviCar Proposal and Related Issues, by Francis D. Reynolds, (9/21/04)
A Perfect Synthesis, by Joshua Zev Levin, (9/15/04)
The Dualmode Transportation Revolution, by Francis D. Reynolds, (4/26/04)
Projected Evolution of Surface Transportation Systems in the USA, by Bruce A. McHenry, (4/9/04)
Electrified Guideways: A More Realistic Vision than the "Freedom Car", by Bruce A. McHenry, (3/9/04)
Individual Mass Transit (IMT), by Jim Beregi, (2/22/04)
Report on a Demonstration of Automated Bus Rapid Transit, by Steven Shladover, 12/27/03
A Hypothetical Evolution of an Automated Highway System, author unknown, 12/21/03
Precise Control of Individual Vehicles, by J. Batelaan, 11/12/03)
Comments on the Automatic Vehicle Control Document, by William Turnbull, located at www.poly-soft.com/irts, by Sergey Prokhorenko, (10/15/03)
Control Software for PRT/Dualmode Systems is a Critical Need, by William Turnbull, (9/28/03)
Multiple-Path Clear-Path Operational Control, by Kim Goltermann, (2/12/03)
Evolution Solves the Chicken and Egg Problem - A Four Point Plan, by Carl Henderson, (2/01/03)
Why Does RUF Use a Special Guideway?, by Palle Jensen, (12/23/02)
A Least-Cost, Least-Disruption Dualmode Concept, by Larry Howe, (12/22/02)
A Reply to Kim Goltermann's Comments on an Individual Rapid Transit System, by William Turnbull, (9/15/02)
Pallets Revisited and Other Dualmode Comments, by Kim Goltermann, (9/11/02)
Realistic Assessment of New Transportation Technologies and System Concepts: Even If You Build It, They May Not Come, by John Hopkins, (8/14/02)
Comments on William Turnbull's Individual Rapid Transit System, by Van Metre Lund, (8/9/02)
I'm Not Unfriendly to Dual Mode, by D. S. Gow, (8/6/02)
Some Thoughts on An Individual Rapid Transit System, by William Turnbull, (8/5/02)
Our National Dualmode Transportation System, by Francis D. Reynolds, (8/4/02)
Abstract: This will respond to a July/26/02 Dualmode Debate item titled DualMode/RUF: My Misgivings An Essay by David Gow, and to his July/30/02 contribution, Dual Mode Debate: Where's the public transit? But first it will expound upon Reynolds' beliefs that a nationwide and worldwide transportation revolution is essential as soon as possible in order to adequately solve the world's transportation and related environmental and petroleum depletion problems. PRT alone would fall far short of the needed revolution.
RUF Dual Mode Public Transport, by Palle Jensen, (8/1/02)
Dualmode Debate: Where's the Public Transit?, by David Gow, (7/30/02)
Rental Cars, PRT and Dualmode Rental Cars, by Francis D. Reynolds, (7/29/02)
Some Questions about Congestion At & Around Dualmode Stations, by Gary Penn, (7/29/02)
Dualmode/RUF: My Misgivings -- An Essay, by David Gow, (7/26/02)
Palletized System Design, by Van Metre Lund, (7/15/02)
Book length description of Francis Reynolds' HiLoMag concept has been completed and is awaiting publication. See the Table of Contents (7/6/02)
Dualmode Station Design (drawing and commentary) as described in a patent issued to Homer T. McCrary, posted by J. Schneider, 6/25/02
Personal Rapid Transit versus Dualmode Transportation, by Francis D. Reynolds, 6/21/02
National Dualmode System Can Help with Oil Supply Vulnerability and Related Problems, by Walt Velona, 10/24/01
Automated Highway System Research on Design, Development and Implementation Issues, by Jerry Schneider, 10/11/01
Whatever Happened to AHS?, by Richard Bishop, 10/10/01
Designing a Second Generation Interstate (I2) Program, by Jim Haugen, 10/6/01
A Response to: Guideway Network Philosophy, by William Turnbull, 8/23/01
Guideway Network Philosophy, by Kim Goltermann, 8/5/01
Guidance, Switching and Freight, by Francis D. Reynolds, 8/4/01
How to Get Off a Dualmode System, by Palle Jensen, 8/1/01
Operation and Control with LSM, by Francis D. Reynolds, 7/30/01
On the Question of Dualmode Scale and Review Process, by Jim Haugen, 7/27/01
Speed Profiles in a Dualmode System, by Palle Jensen, 7/27/01
Dualmode System Implementation in Big Cities, by Palle Jensen, 7/26/01
Moving Ahead on Dualmode - A Different Approach, by Jim Haugen, 7/24/01
Platooning, Car Coupling and LSM, by Francis D. Reynolds, 7/24/01
A Response to: Operational Control, Hardward and Network Issues, by William Turnbull, 7/18/01
Should Dualmode Concepts Give Priority to Intercity Travel or Intrametropolitan Travel Problems?, by Jim Haugen with a response from Bill Turnbull, 7/14/01
What is the Purpose of Dualmode?, by Palle Jensen, 7/12/01
Pre-Platooning and Fixed-Origin/Flexible Destination Pairs, by Charl du Toit, 7/10/01
WHSSSH - A Trustworthy 150 mph Automated Highway System, by Jim Haugen, 7/7/01
Operation, Control, Hardware and Network Issues, by Kim Goltermann, 6/22/01
Dualmode Will Fix or Reduce Many Problems, by Francis D. Reynolds, 4/13/01
Dualmode and Automated Highway Systems (AHS), by Brian Dudson, 4/5/01
Coupled Platooning: Merely Desirable or a Necessity?, by Charl du Toit, 4/2/01
Some Thoughts on Operation and Control, by William Turnbull, 3/27/01
Why Doesn't RUF Use Linear Motors?, by Palle Jensen, 3/13/01
Abstract: Linear Induction Motors (LIM) and Linear Synchronous Motors (LSM) are non-contact motors. This attribute has some important advantages for a transport system. Nevertheless, the arguments against using LIM/LSM motors in a Dual Mode system are too strong.
A New Proposed Configuration for the National Dualmode Guideway System, by Francis D. Reynolds, 3/10/01
Abstract: This article discloses a simple new dualmode vehicle and guideway configuration, and makes comparisons between this configuration and the configuration Kirston Henderson proposes. It also includes an e-mail from Dr Richard Thornton to Reynolds, and addresses some opinions expressed by Dr. J. Edward Anderson in his recent debate contribution.
Capacity in a RUF System, by Palle R. Jensen, 3/4/01
Abstract: Capacity is a complex issue. It is not enough to compare numbers. Capacity comes in different qualities. In a network capacity is more complicated than traditional line capacity. This article tries to shed some light on the capacity issue seen from a RUF standpoint.
Problems of Single Mode Transportation, by Palle R. Jensen, 3/3/01
Abstract: Dual Mode is more complex than Single Mode. Dual Mode can do the same as Single Mode plus something more. As a natural consequence it will be more complex. The good question is: Is Single Mode enough to solve the traffic problems of modern societies ? I think the answer is NO.
The Case for True Maglev Dualmode, by Walter Velona, 2/24/01
Abstract: Outlines a plan to build 100,000 miles of intercity maglev guideway and 60,000 miles of urban maglev guideways that will link most of the neighborhoods of the country. For the rest of this century, use of the guideway will cut automobile capital costs in half and provide the funds for building the system. Energy costs are also reduced. Requests government assistance to initiate the maglev dualmode system by developing the technology and building the initial increment on the Interstate Highway System. Proposes user payment of capital costs by selling permits that allow use of the guideway during the life of the car.
Problems of Dual Mode Transportation, by J. Edward Anderson, 2/19/01
A Reaction to Mr. Turnbull's Criticism of My True-Dualmode Enthusiasm, by Kim Goltermann, 2/19/01
Implementation Strategy for RUF Dualmode, by Palle Jensen, 1/28/01
The RUF Standard: Some Preliminary Considerations, by Palle Jensen, 1/28/01
A Response to Mr. Goltermann and True-Dualmode, by William Turnbull, 1/26/01
Implementing True Dualmode: Can It Be Done?, by Kim Goltermann, 1/25/01
A New Transportation Mode Must Reduce the Problems of Current Transportation Modes, by Johan Overvest, 1/17/01
Dualmode and the Facts of Life, by Francis D. Reynolds, 12/15/00
Abstract: This article is a response to Donald Richardson Arthur's item of November 30. Reynolds acknowledges that Richard Arthur, Hopkins, and other realists are right in their arguments that under ordinary circumstances building an extensive dualmode system for the United States would be next to impossible. However, Reynolds points out that we have extraordinary circumstances, and therefore the system will be possible by the special means he proposes here. This contribution also touches upon several related issues addressed by William Turnbull on December 12.
An Argument for Pallets, by William Turnbull, 12/12/00
Abstract: The controversy between the so-called true and palleted versions of dualmode continues. However, there is little, or no, empirical evidence upon which to base an informed choice. Moreover, there are multiple issues which also must be resolved before a truly optimum design can be developed. Given the novelty and scope of this design problem, more than a single approach should be pursued. Only palleted dualmode provides the flexibility and the unambiguous central authority to accommodate the objective.
Variable-Pole-Pitch Linear Synchronous Motors and their Potential in Automated Transportation Systems, by Francis D. Reynolds, 12/05/00
Abstract: This is a partial rebuttal to an e-mail message from Markus Szillat, University of Bristol, UK, January 5, 2000, to myself with copies to others. Part of my long delay in responding is due to the fact that Markus pointed out a potential problem in the ramps of the hypothetical HiLoMag system that I did not have a good answer for at that time. Now I do. The concept named in the title above is believed to be unique, practicable, and well suited for use in the offline acceleration ramps of transit and dualmode systems using LSM on the guideways. As with all HiLoMag concepts, this invention is being placed in the public domain.
Also included is further material on the use of and the advantages of synchronous guideways with asynchronous ramps.
Comparative Cross-Section Graphic for MegaRail and Other Technologies, by Kirston Henderson, 12/1/00 (includes estimates of emergency walkwalk solutions for each technology)
Palletized Cars Can Help Us Move Forward, by Richard Arthur, 11/30/00
Future Solar Energy Utilization for Transportation, by J. Richard Guadagno, 11/27/00
Chauffeur Distribution in a RUF Dualmode System, by Palle Jensen, 11/01/00
Why RUF Should Use Maglev, by Francis Reynolds, 10/16/00
Abstract: This is a rebuttal to Palle R Jensen's contribution of October 4th, where he gave his reasons for rejecting maglev in his dualmode RUF system.
Automated Transport: Where to Start?, Where to End? PRT, "True" Dualmode, Palletized Dualmode, Maglev or What? Can We Get Together On Standards and Present a United Front?, by Van Metre Lund, 10/16/00
Abstract: Autran systems initially built for carrying autos on pallets can help solve immediate and serious problems with use of automobiles, could be compatible with PRT systems and could also be compatible with "true" dualmode systems although such systems appear to have serious problems particularly with respect to costs. The modular construction of Autran systems could facilitate development of standards and help lead to nationwide automated transportation system for carrying passengers in passenger cabins, autos on pallets and freight containers.
Response to "Dualmode System Design Odds and Ends", by Kim Goltermann, 10/16/00
Why RUF is not a Maglev System, by Palle Jensen, 10/4/00
Abstract: The article describes the main reasons why the RUF system uses wheels on the guideway instead of magnetic levitation.
Dualmode system Design Odds and Ends, by Francis Reynolds, 10/3/00
Abstract: Firestone tires on the guideways? The dualmode fraternity needs maglev engineering knowledge. Maglev with linear motors is excellent technology that is ready for use in the national dualmode system. Our present fraternity will not design the national system, but we can introduce the concepts and influence the design. Slow freight is cheap transportation; fast freight needs justification. Coal or solar power to make guideway electricity? The switching of cars on the guideways will be easy, even with very close headways and very high speeds. The national dualmode system should be designed to solve or reduce as many problems as the concept is capable of. The guideways should accept both pallets and true dualmode vehicles. The ramps should not be owned by the guideway system. Dualmode taxis and dualmode rental-cars will eliminate the need for PRTs.
More Thoughts on Pallets and True Dualmode: A Second Response to Van Metre Lund, by Kim Goltermann, 9/26/00
Public Transit in the Dualmode Era: Introducing a Public Transit Revolution, by Kim Goltermann, 9/26/00
Palletized Dualmode IS an Answer: A Response to Kim Goltermann, by Van Metre Lund, 9/15/00
Pallets are not an Acceptable Solution for Dualmode Capability, by Kirston Henderson, 9/15/00
Abstract: Pallets are not acceptable for providing a dualmode capability and should only be considered as a short-term element that will eventually fall into disuse. True ferry vehicles onto which cars can be quickly driven are preferred over pallets because of reduced loading time reduced terminal costs. A true dualmode electric car must be provided that operates both on streets and on the automated guideway and recharges it batteries during guideway operation. The dualmode car must use the same propulsion and suspension systems for street and guideway use in order to be built within acceptable complexity, cost, and weight limits. Provision of separate suspension and propulsion systems such as those necessary for maglev are probably impractical.
Some Pallet Calculations: A Response to Van Metre Lund's Claims, by Kim Goltermann, 9/13/00
Palletized System No, but Pallets per se OK, by Francis Reynolds, 9/11/00
Abstract: Kim Golterman is right in his contribution of Sept 7: The disadvantages of a system that provides separate pallets are overwhelming; a palleting dualmode system would not be optimal. The recent switch in thinking on HiLoMag, where we deviated from a supported true-dualmode-car system, was a mistake. The HiLoMag system is again proposed to have guideways supporting the cars from below, and to use true-dualmode cars. Additional comments are made on the configuration of the guideway and the interfacing parts of dualmode cars. The thought of separate rental pallets for use with standard automobiles or special loads is introduced. Private companies would offer the occasionally used rental pallets, not the guideway system.
Palletized Dualmode IS an Answer, by Van Metre Lund, 9/8/00
A Few Thoughts on Palletized Dualmode, by Kim Goltermann, 9/7/00
Even More Thoughts on Guided Personal Transit, by William Turnbull, 9/5/00
Comments on Walt Velona's Proposed Letter to the U.S. President, by J. Richard Guadagno, 9/4/00
Pros and Cons of RUF Dualmode, by Palle Jensen, 9/3/00
Response to Kim Goltermann's Comments, by Kirston Henderson, 8/31/00
Pros and Cons, by Kim Goltermann, 8/30/00
More Thoughts on Guided Personal Transit - A Response to William Turnbull, by Palle Jensen, 8/29/00
Some Thoughts on Guided Personal Transit, by William G. Turnbull, 8/28/00
Solar Power for Sustainable Transportation Systems, by J. Richard Guadagno, 8/24/00
Dualmode-PRT Design Considerations, by Walt Velona, 8/24/00
Dualmode and PRT Guideway Loading and System Planning Considerations, by Walt Velona, 8/16/00
Choices, by Francis Reynolds, 8/10/00
Private versus Public Ownership of a National Dualmode System, by Walt Velona, 7/30/00
Searching for a Viable Transition Path, by Kim Goltermann, 7/27/00
Searching for the Optimum Dualmode System: Continued, by Francis Reynolds, 7/22/00
Affordable Dual-Mode Vehicles and Systems, by Palle R Jensen, 7/16/00
Searching for the Optimum Dualmode System: A Response, by J. Richard Guadagno, 7/15/00
Reynolds' Optimum Dualmode Concept is a Loser, by Kim Goltermann, 7/15/00
Searching for the Optimum Dualmode System, by Francis Reynolds, 7/5/00
Further Critique of the Automated Highway System and MegaRail Concepts, by J. Richard Guadagno, 6/29/00
Reaction to Francis Reynold's "True Dualmode vs. PRT and Palleted Dualmode Concepts, by A. Steingroever and R. Krevet, 6/26/00
Response to True Dualmode Vehicle Commentary by Reynolds, from a MegaRail Point-of-View, by Kirston Henderson, 6/25/00
True Dualmode Cars vs. PRT and Palleted Dualmode Concepts, by Francis Reynolds, 6/20/00
Reaction to J. Richard Guadagno's Comments Regarding Essential Requirements and Setting the Record Straight Regarding His Megarail Misconceptions, by K. Henderson, 6/19/00.
Critique of MegaRail's Essential Requirements as Described by Henderson, by J. Richard Guadagno, 6/00 (see below: An International Multimodal System Can and Will be Built, by K. Henderson, 5/00).
Evaluation of the AHS Article by Steven Shladover, by J. Richard Guadagno, 6/00
Critique of the Paper by Steven Shladover Regarding the Problems and Potentials of the Automated Highway Concept, by Kirston Henderson, 6/00
The Odds in Getting a National Dualmode System, by Francis Reynolds, 6/00
Response to Comments by Francis Reynolds to my Critique of the Concept of a National Dualmode Transportation System, by John B. Hopkins, 6/00
What If Cars Could Drive Themselves?, by Steven Shladover, 6/00
Cheap versus Effective Dualmode Transportation, by Francis Reynolds, 6/00
Reactions to the Comments by Hopkins with Respect to the UTI Dualmode Concept, by Jim Beregi, 5/00
An International Multimodal System Can and Will be Built: A Response to Comments by Hopkins, by Kirston Henderson, 5/00
Response to Comments by Hopkins with Reference to the FlexiTrain Dualmode System, by Charl du Toit, 5/00
Can a Dualmode System be Implemented? Response to Comments by Hopkins with Respect to the RUF Dualmode System, by Palle R. Jensen, 5/00
Response to Comments by Hopkins with Reference to the Autran Dualmode Concept, by Van Metre Lund, 5/00
Response to Comments by Hopkins with Reference to the InTransSys Dualmode Concept, by J. Richard Guadagno, 5/00
Response to Comments by Hopkins with Reference to the Autobus Dualmode Concept, by William Bowen, 5/00
Discussion of the Problems and Potentials of a National-Scale Dualmode System, by John Hopkins and Francis Reynolds, 5/00
Response to Guadagno's Response, by Joerg Schweizer, 3/00
Response to Schweizer's InTransSys Critique, by J. Richard Guadagno, 2/00
Critique of the InTransSys Dualmode Concept, by Joerg Schweizer, 2/00
Dualmode vs. Single Mode : Which Approach is More Likely to Succeed?, by Francis D. Reynolds, 11/98
The Quadmode, Modular Approach to the Ground Transportation Problem, by Gary Webber, 9/98
Overcoming J.E. Anderson's Arguments Against Dualmode Transportation, by Tad Winiecki, 9/98
On Making the Transition to Dualmode , by Palle R. Jensen, 4/98
A Proposed Transition Path to an Advanced Dualmode System , by Larry Stern, 4/98
The Advantages of Dualmode Transportation , by Francis Reynolds, P.E., 4/98
Some More Musings on Dualmode versus Singlemode PRT , by Dennis Manning , 4/98
Response to Anderson's Dualmode Critique , by Palle Jensen, 4/98
Dual Mode Musings , by Dennis Manning, 3/98
Automated Public Vehicles , by Michel Parent, 3/98
The Dualmode Car Bus is the Best Solution , by Dave Petrie, 3/98
A Dualmode Developer's Views , by Jan Andress, 3/98
Dualmode Critique , by J.E. Anderson, 3/98
Let's Agree to Head Toward a Dualmode Solution , by Joe Palen, 2/97
Last modified: August 01, 2017