Dual Mode Vehicle and Infrastructure Alternatives Analysis

                                     by Christine Ehlig-Economides and Jim Longbottom, April, 2008

                               Published by the Texas Transportation Institute, Texas A&M University

                                           Full report (136 pp) is available on-line (about 3 megabytes)

The definition of a Dual Mode transportation system used in this report is as follows:

Dual mode: A vehicle/infrastructure design that allows vehicles in one mode to navigate ordinary roads under driver control and in a second mode enter a guideway where electric power is provided to the vehicle in real time and the vehicle is computer controlled.

Here is a video description of one type of Dual Mode transportation, called Quiklane


The United States wastes over $1.5 billion per day due to inefficiencies in the current highway transportation architecture. This waste includes:

  1. $189 billion per year premium in energy costs due to the 98.5 percent transportation dependence on a single primary fuel (oil);
  2. $230 billion per year due to deaths, injuries, and property damage caused by safety issues;
  3. $64 billion per year due to congestion causing excess fuel consumption and lost productivity;
  4. $17 billion per year due to air emissions;
  5. $33 billion per year in international energy security expenditures; and
  6. $75 billion per year in lost productivity and foregone supply chain improvements that could be enabled by faster, more reliable mobility of people and goods.

A bold solution to these challenges may exist in the form of a dual mode electrified transportation network. This concept merits a critical mass research effort to evaluate the cost/benefit balance, identify and address the technology challenges, analyze the transition pathways to the alternative architecture, and ascertain the policies and coalition support mechanisms that would enable the vision to become reality.

A proposed new national network uses single and dual mode vehicles to provide mobility for freight, private cars, and mass transit vehicles. In single mode, the vehicles will be captive to an electric guideway from which they draw propulsion energy in real time as the vehicle moves at high speed under automated computer control. Single mode applications could include fully automated (driverless) terminal-to-terminal freight transport and personal rapid transit. In dual mode operation, driver-controlled vehicles will be able to travel the first and last miles off-guideway using onboard energy storage as one mode and then enter the guideway in a second mode for high speed automated travel.

The mixed-use nature of the guideways provides multiple revenue streams to pay for the infrastructure, as is currently the case with highways. Shorter headway distances and higher steady speeds combine with costs per mile similar to highways to provide more throughput capacity per infrastructure dollar invested. A generally elevated and lightweight infrastructure is envisioned, enhancing safety and minimizing footprint so that current highway or railroad rights-of-way could be sufficient for much of the national network.

Any primary fuel capable of generating electricity will be able to compete for the transportation energy market. The resulting competition between primary fuels to satisfy the transportation energy demand may accelerate innovation in this arena while also enabling better solutions for control of air emissions.

In addition, the research team offers the following four options that can be employed by the Texas Department of Transportation (TxDOT), with each option exhibiting higher degrees of engagement, leadership, and influence in defining future transportation alternatives:

1. Passively monitor dual mode technology developments and advise TxDOT decision makers when the technology maturity is approaching commercialization. This option will leave TxDOT with little influence or leadership in steering the technology to meet Texas’ needs.

2. Directly sponsor in-depth studies of the impact on Texas from development of dual mode with matching industry funds required for the studies. This option will provide TxDOT with some influence and leadership and will send clear signals to the private market of receptivity to new solutions.

3. In addition to the impact studies of option two, provide testbed sponsorship from state funds to match private investment to ensure Texas shares in the lead of new energy and transportation solution development.

4. In addition to Texas-supported impact studies and testbed facilities, engage the Texas governor and the U.S. congressional delegation to make this a federal initiative with multi-state support.

It is in Texas’ interest to lead the nation in this transition to maintain our position as the "energy capital" of the nation. To take the leadership role, a first phase of development should provide a baseline system concept/design and robust modeling of the expected impact in the following areas: economic development, electric demand, emissions, congestion, safety, energy flows, emergency preparedness, and transportation planning and policy. The researchers recommend adopting option two of the alternative pathways. Based on a positive outcome from the initial analyses, the following recommendations may be advanced:

  1. Engage the private sector in implementing the new mode with the goal of a 20-year full implementation of a national system, which should be explored to achieve a new level of energy security by 2035. A relatively quick transition to the new architecture will have network benefits that will encourage rapid end user adoption of the new technology.
  2. Should initial impact and cost/benefit studies prove feasible and attractive, TxDOT should encourage design and operations standards that ensure interconnection between intercity systems justified by freight and intracity systems justified by transit, thereby providing a navigable critical mass network for dual mode private vehicle technology adoption.
  3. Leverage political support from the state to develop availability of federal matching funds for dual mode electrified transportation technology acceleration.

A policy of enabling more robust transportation energy competition should be adopted. There is no current corporate monopoly in oil, but oil as a resource has a monopoly in transportation energy markets. A policy of encouraging the move to electrification for transportation energy will increase competition and spur productivity improvements and innovation.

Development of a dual mode electric transportation infrastructure should be explored as an opportunity to harden and increase the electric transmission and distribution capacity while also delivering new solutions for emergency response and homeland security.

Approach the challenge in step-wise fashion, with further efforts focused on four thrusts:

  1. a technology roadmap,
  2. systems-level technology adoption and impact modeling,
  3. a financial and policy framework, and
  4. organization of a research and development consortium.

The technology roadmap efforts would address system performance and integration issues, power delivery, vehicle systems, surface superstructure, command and control systems, and networked sensors and system health monitoring. Modeling efforts would include energy, emissions, transportation demand, economic impact, emergency response, and system dynamic modeling. Financial and policy analysis would clarify pathways to critical mass support for a transition to a 21st century transportation network. Finally, organizational development is needed to define a pre-competitive space in which collaboration among competitors can be achieved for the benefit of all collaboration partners while guarding the assurance of robust competition for actual delivery of products to the market. A consortium dedicated to the launch of this initiative is recommended and may follow the business model of the SEMATECH collaboration, which operates in the semiconductor fabrication space, or the FutureGen Alliance, which is organized to demonstrate clean coal technologies to a commercial scale.

Click here to see the Table of Contents for this report

For descriptions of and website links to several Dual Mode systems currently being developed around the world today, click here


                                                                      Last modified: May 24, 2008