Whatever Happened to Automated Highway Systems (AHS)?

by Richard Bishop

Originally published in the August-September 2001 issue of Traffic Technology International. Posted with their permission.

ahsgraphic1.jpg (73164 bytes)As one of the ultimate goals of the original definition of Intelligent Transportation Systems, the idea of Automated Highway Systems (AHS) was 'all the rage' during the 1990s, as US DOT sponsored an ambitious program carried out by the National Automated Highway System Consortium (NAHSC). This work culminated in the celebrated Demo '97, in which more than 20 fully automated vehicles operated on 1-15 in San Diego, California, without a hitch, giving thousands of ITS professionals and public officials a taste of the future.

The press loved it - this event still stands as gaining the most media coverage of any ITS activity, before or since, and the video clips still show up regularly on television technology shows, including in July this year in the UK on the BBC programme 'Speed'. Based on the response to this and several other demonstrations since, the public is enchanted with the idea of an 'electronic chauffeur' that would take care of the tedium of driving while the driver rests or attends to other tasks. This image is part of the Utopia that always hangs 'out there' in the future somewhere. Those audacious enough to try to bring these visions to reality have had their share of tribulation, and AHS is no exception - USDOT cancelled the NAHSC program in 1998, citing budget pressures and the greater importance of near-term safety systems.

So what has happened in the four years since August 1997, when the NAHSC and their partners dazzled the world with automated cars and transit buses? Is there any life out there for this concept? The answer is a yes - while the landscape has shifted dramatically in terms of focus and players, the prospect of automated vehicles in service to society has continued its momentum. What follows are some observations on the trends afoot, along with a tour of the activity in vehicle-highway automation programs worldwide.


*What you want is not what you get. Shoving all the technology advocates out the back door for a bit, let's do this right and look at the user side of the equation. What does the public want in the way of highway transportation? Ask any local or regional political official - the public wants to be rid of traffic congestion. Smooth traffic flow is at the top of the 'wish list' for countless transportation officials - although many do not think it is actually possible. A recent cover story in US News and World Report titled 'American Gridlock' vividly laid out the extent of the problem, the level of frustration for Americans and the sense from many respected experts that we will just have to learn to live with pervasive congestion. A panel of US experts said the same thing in testimony to Congress earlier this year: congestion is here to stay.

Although greater safety is always welcome, and is indeed rolling out steadily from the vehicle industry, one does not see strident calls for increased safety at the political level, because the public is not clamoring for it. People seem to be satisfied with their personal level of safety on the road, even while being aware of the tens of thousands killed annually through traffic accidents. Nevertheless, major government-industry programs to develop driver assistance systems to enhance safety are right on target in addressing this key societal issue.

So, an argument can be made that the user demand exists for any approaches which ease driving and reduce congestion. Congestion erodes quality of life to a major extent, in the same way that air pollution erodes public health. Do we just give up and live with it? Not for some. "We believe vehicle-highway automation is an essential tool in addressing mobility for the citizens of California," says Greg Larson, head of the Office of Advanced Highway Systems with the California Department of Transportation (Caltrans), who notes that the construction of new roads, in general, is simply not feasible due to cost and land constraints. The same sort of refrain can also be heard in Asia and Europe.

This is not your father's AHS.

If you followed the AHS hoopla during the 1990s, you heard a lot about 'dedicated lanes' and 'platooning'. AHS implementation came to be tagged with the idea of construction of specialized infrastructure for all those fancy cars, which left infrastructure providers scratching their heads as to how they would squeeze in these lanes, even if the benefits were large. The prospect of vehicle platoons, which made for such startlingly eye-catching video clips, was difficult to swallow on a practical basis for many. After all, it is quite a stretch just to envision automated cars becoming reality, and to then to think of being compressed into a close-headway platoon made it a tough sell.

A kinder, simpler system

From discussions with experts around thi world, a first-generation of vehicle-highway automation is coming into focus, in which automated vehicles operate on today's roads with no extensive infrastructure modifications required. Early co-pilot systems would evolve to auto-pilots gradually. These vehicles would operate at spacings a bit tighter than commuter flows of today, with traffic flow benefits achieved through vehicle-cooperative systems as well as vehicle-infrastructure cooperation.

The vehicles may cluster in 'designated lanes' which are also open to normal vehicles, or may be allowed on high-occupancy vehicle (HOV) lanes to increase their proximity to one another and therefore get the benefits of cooperative operations (access to HOV lanes also creates a powerful incentive for consumers to invest in these systems). Stabilization of traffic flow and modest increases in capacity are seen as the key outcomes.

Once this level of functionality is proven and in broad use, a second generation scenario comes into play which expands to dedicated lanes, presumably desired by a user population with a high percentage of automation-capable vehicles. With growing use, networks of automated vehicle lanes would develop, offering the high levels of per-lane capacity achievable through close-headway operations.

Now, depending on who you talk to, this type of evolution could take a while. First generation vehicle-highway automation for passenger cars is at least 10 years away, with estimates for second generation implementation hovering around 2025. Although many years away, this time horizon is definitely not too far out for transportation planners to consider the advent of such capability in their long-range planning processes. But if you have the inclination, a vehicle with automated capability could be available from a car dealer near you much sooner.

The World Congress in Turin last year vividly demonstrated that driver assistance systems have graduated from R&D curiosities to the realm of product development. Both European and Japanese car-makers are known to have active programs focused on automated driving. This is seen as a natural evolution of the safety and convenience systems they are bringing to market, such as adaptive cruise control and lane departure avoidance. In fact, Low Speed Automation (LSA) systems - which take over full vehicle control in congested stop-and-go traffic - could be available within five years or so. But even with an automated vehicle you may have the maximum in convenience, but no help with the time spent in traffic jams - the cooperative vehicle-highway systems cited above must come into play to accomplish benefits for the aggregate traffic stream.

Automation in the near term

Public transport is acting as the prime incubator for automated vehicle systems in the near-term. Travelers in the Netherlands are now served by the ParkShuttle, an unmanned automated vehicle which shuttles people between parking lots and the airport terminals at Schiphol Airport in Amsterdam; it is also in use at an office complex in Rotterdam.

Semi-automated bus systems are now being developed for Eindhoven in the Netherlands and the French cities of Clermont-Ferrand and Rouen. In the states, automatic guidance is a key component of the Bus Rapid Transit concept being advanced by the Federal Transit Administration. Over a dozen US transit agencies are involved in the BRT Consortium, and several are actively considering automated guidance for precision docking (to improve efficiency in passenger loading) and exclusive lane operation in narrow, confined corridors. Implementation of automated guidance is underway in Las Vegas and is expected to begin soon in Eugene, Oregon, Hartford, Conn. and Cleveland, Ohio (see the FTA website for details).

Another pioneer in automated public transport is Toyota, which has developed the Integrated Multimodal Transport Systern (IMTS). Demonstrated at Demo 2000 last December in Japan, the IMTS uses AHS technology to operate several buses in close-headway platoons, all under automated control. The system is slated to begin service this year, serving transit needs at a major theme park in Japan.

Long-term traffic efficiency

Will high-volumes of cars moving smoothly under automated control ever be part of our future? Here's one way to look at it: at some point along the way it appears inevitable that automated vehicle operation will be offered by the auto manufacturers. Given the information flowing in and out of cars with the parallel implementation of telematics, it seems natural that these vehicles would start conversing with each other, enabling precise inter-operation and smoother traffic flow. And, given increasingly sophisticated traffic management centers, it again seems natural that TMC's would want to be in direct contact with vehicle control systems to optimize the traffic flow. The only question is, will the public sector be proactive in taking advantage of this capability, so that the benefits come sooner rather than later?

The strength of the US NAHSC program gave momentum to aid in the establishment of similar programs worldwide. As USDOT has faded from the scene, other countries have continued their efforts, and R&D is moving forward at a steady pace.

Asian cooperative systems

One of the most active and well funded players in this arena has been Japan's Advanced Cruise-Assist Highway System Research Association, (AHSRA)  which brought together the key automotive, infrastructure, and electronics companies in a partnership with the Ministry of Land, Infrastructure and Transportation within the Japanese government. Shortly after its founding in 1996, AHSRA defined three levels of focus - AHS-i (information to the driver), AHS-c (control assist for the driver) and AHS-a (fully automated operations). Work since then has focused on cooperative intelligent vehicle-highway systems for crash counter-measures, culminating in the an impressive Demo 2000 last December in Tsukuba City. Here, 38 cars, buses and trucks illustrated 'the ideal system for reducing road traffic accidents' using driver information and control assist systems.

AHSRA strongly supported the near-term development of standards to enable these cooperative vehicle-highway systems to move into full deployment. It also turned its focus to evolving these systems for improvements in traffic efficiency on Japan's heavily congested roads. It does not appear that AHSRA is still active but some of its materials may be viewed at a collection of archived papers.

South Korea constitutes the other major center of focus for Asia. Automated vehicle research has been spear-headed by Korea University and the Korea Highway Corporation has published a National ITS Master Plan which includes an 'Advanced Highway and Vehicle System,' of which automatic driving is a component.

Europe's big picture approach

Big-picture approaches to vehicle-highway automation can be found in several European programs, which collectively add up to a significant level of activity.

Several years ago, the French government initiated a program called 'La Route Automatisee', which performed preliminary studies towards the application of vehicle-highway automation to improve travel in rural areas, commercial trucking, city-to-city corridors, and commuting. In 1999, the Laboratory for the Interaction Between the Vehicle, Infrastructure and Driver (LIVIC) was co-founded by the National Research Institute for Transport and Safety (INRETS) and the Central Laboratory for Roads and Bridges (LCPC).

LIVIC is currently a key player in the CARSENSE project funded by the European Commission, which is developing sensor fusion techniques to enable vehicles to intelligently operate in complex urban environments, as enabling work towards realizing low-speed automation. Within France, new work is going forward under the ARCOS program, which lays out a comprehensive path from today's safety systems, to cooperative vehicle-highway systems, to fully automated networks serving travel needs in future decades. With approximately Euro l5 million (US$13 million) in funding, ARCOS 2003 is focusing on autonomous vehicle safety systems, vehicle-vehicle communications for safety, and vehicle-infrastructure communications. And mark your calendars - LIVIC and the National Research Institute for Information and Automation (INRIA) are hosts for a set of vehicle demonstrations in conjunction with the Intelligent Vehicle Symposium to be held in June 2002 in Versailles.

Early on, the Dutch took a leadership role in sponsoring Demo '98, which focused on showing government policy officials the potential of intelligent vehicle systems. Demo '98 has now borne fruit in a funded program for Advanced Driver Assistance (ADA) pilots, which is being conducted by the AW Transport Research Center within the Department of Transport, Public Works, and Water Management. Program manager Edwin Bastiaensen is now launching a pilot focused on lane-keeping assistance for drivers, which the Ministry hopes will be an enabler towards implementing dynamically configured narrow lanes to create additional road capacity in heavy traffic conditions. Also in the works are additional pilots for Autonomous Speed Assistant and External Speed Assistant, the latter of which could be used by freeway managers in smoothing traffic flow and enhancing efficiency. The Ministry is hosting another demonstration around September 2002, to showcase the Lane Departure Warning pilot vehicles and other ADA systems from around Europe.

The British have looked at AHS as part of a 'VISION 2030' process, which included full-scale AHS systems in the long term to handle massive traffic flows. Last year, the Highways Agency (HA), within the Department of Transport, Local Government and the Regions (DTLR) initiated a study to examine user attitudes to AHS, in which a majority of respondents indicated an openness to the concept. Overall, the UK is currently exploring the merits of developing a longer term research program to increase the scope of use of intelligent vehicle-highway systems.


Probably the most high-profile vehicle automation project in Europe in recent years has been CHAUFFEUR, which has implemented 'electronic tow-bar' operations for heavy trucks. In 1999, project engineers demonstrated this basic capability on public highways in Germany, in which a lead truck, driven normally, was followed by a second truck under fully automated control. This was accomplished with radar-sensing, infrared signatures and vehicle-vehicle communications.

Benefits studies have shown that this type of operation can increase fuel economy (up to 20 per cent) and reduce the traffic impediments caused by trucks (up to 8 per cent improvement in capacity). CHAUFFEUR II began early this year and is implementing the capability to entrain behind any type of vehicle and also platoon multiple trucks. Funded by the European Commission, CHAUFFEUR partners include DaimlerChrysler (lead), IVECO, and Renault VI.

Pan-European work in this area has been centered in two programs, Advanced Driver Assistance Systems for Europe (ADASE) and RESPONSE. With broad participation throughout the continent from both government and the vehicle industry, ADAS has provided a forum for defining levels and types of driver assistance, culminating in 'autonomous driving.' ADASE began under the EU Fourth Framework program and now ADASE II is continuing development of deployment paths and studies of key issues.

RESPONSE plays a unique and valuable role in the evolution of the Advanced Driver Assistance System (ADAS) by addressing the many institutional, societal, and user issues that arise when vehicle control is shared between drivers and intelligent systems. Vehicle manufacturers, automotive suppliers, human factors experts, legal experts, and public policy researchers have been involved in the project. RESPONSE has produced concepts for the interaction between system safety, safety of usage, and product liability. They have analyzed legal aspects of testing and market introduction of ADAS, validation procedures for the user-centered assessment of ADAS have been developed, and recommendations for functional specifications, standardization, and type approvals have been generated.. One key output of Phase I has been a Recommended Code of Practice for ADAS, expected to be adopted European-wide. RESPONSE II is now in its formative stages and the program will examine issues which arise with the introduction of more advanced forms of ADAS, seeking to identify any impediments and smooth the way forward. RESPONSE is led by Dr Stephan Becker of TUV Rhineland in Germany.

Born in the USA ...

Looking back to the United States, California, the original locus of AHS research, continues undaunted by US DOT's current lack of investment. R&D is continuing via the California PATH program at the University of California - Berkeley. Concluding that implementation must first be successfully rolled out on trucks and transit buses, Caltrans is funding PATH to develop electronic tow-bar systems for trucks and platooning systems to create the equivalent of 'bus trains.' Caltrans believes that the public will become familiar with vehicle-highway automation systems as it comes into usage on these professionally-driven vehicles, which will assist in creating demand for systems for the everyday automobile.

The agency is sponsoring a major demonstration of these capabilities in 2003 - the commercial vehicle and transit industries are the key audience, and the timing is also geared to influence Congress as it considers new legislation to guide national transport research.

California is also active on a national basis, having recruited 10 other states to join them in the Cooperative Vehicle-Highway Automation Systems (CVHAS) pooled fund research study. This effort is also open to the private sector, with Honda R&D as the first member. With a budget of around US$ 300,000 per year, the early focus of the CVHAS group is in performing simulations and case studies for deploying freight and public transport systems. The group is also expected to be quite vocal with Congress in the developing national debate about national priorities for the next phase of ITS research.

And what about US DOT? Their Intelligent Vehicle Initiative program is considered to be quite robust and successful, focusing almost exclusively on autonomous vehicle safety systems. A minute but continuing stream of investment in cooperative vehicle-highway systems has been retained from the AHS days, under the leadership of Bob Ferlis of the Federal Highway Administration. But officials admit that currently, there is no focus on going beyond safety to use these technologies as a tool for addressing traffic flow - currently, there is no clear 'home' within the Department for this concept.

But things will get interesting over the next couple of years, as the Department enters into an intense period of listening sessions and policy development in preparing the Bush Administration proposal to Congress for transportation authorization legislation to succeed the current TEA-21.

Some IVI program officials envision that this 'TEA-22' period is the right time to invest heavily in cooperative vehicle-highway systems. But this is expected to be a gradual process - fundamentally, freeway managers, whose mission it is to deliver smooth traffic flow, typically don't think in terms of vehicle-highway cooperation as part of their tool box. In the US, the constituency is slowly developing, thanks to efforts like CVHAS.

Keeping it together globally

Beginning at Demo '97, a group called the International Task Force on Vehicle-Highway Automation has met annually to enable leaders of these programs to compare notes, share research results, and discuss global approaches to this new tool for society. Representatives from Australia, Canada, the European Commission, France, Germany, Italy, Japan, South Korea, the Netherlands, the United States (in particular California and Minnesota) and the UK are regular participants. The group is meeting at the ITS World Congress in Sydney for its 5th annual meeting.

All in all

So, to finally return to the original question. What happened to AHS? It has morphed into multiple new forms, with precursor systems virtually on our door-steps, and the ultimate 'system' a set of innovations that may enter the transportation mix so naturally over the years that it will not attract much notice.

And, the original concept has dispersed itself into numerous programs worldwide and adapted to needs of individual regions. While funding for these national programs is typically modest at best, taken on a global scale, the momentum is impressive. As long as traffic demand exceeds supply, congestion will occur, but if these researchers and government visionaries can stay the course, a new and powerful factor can be added to the supply side of the equation.

Richard Bishop writes about intelligent vehicle-highway systems at www.IVsource.net and consults with the vehicle industry, technology providers, and government agencies regarding emerging applications and partnership development in this arena.

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Last modified: May 01, 2011