For the last century the transportation industry has been focused on the supply of infrastructure to support the ever growing fleet of vehicles and the greater number of miles covered by each vehicle. Our focus has been planning, funding, designing, building and maintaining roadways. Politicians, engineers, planners, financial managers … all of us have had this focus. We have experienced demand growth since the first model T was launched from the factory. Congestion in urban areas, safety and the economic need to move people and goods and to compete in a global economy has driven our thinking. The ability to supply infrastructure has been the measure of transportation performance.
Roadways and transit properties are public goods. They are generally built by government, maintained by government and funded by gasoline tax revenue, though tolling has grown in prominence because of the inadequacy of tax revenue to satisfy ever increasing demand. Transportation has been a public works effort administered by public agencies with a substantial institutional momentum that has kept the planning focus on supply. It is a highly regulated, standardised and lengthy process with enormous political, social and economic implications. In recent years, we have begun to use managed lanes in an attempt to meter demand and policy has been developed around the management of demand. In effect, the transportation community has begun to ‘operate’ infrastructure through price controls based on occupancy and congestion levels.
Autonomous vehicles
The development of autonomous vehicular travel will however modify the collective demand for transportation infrastructure in ways that have perhaps not been fully appreciated. The deployment of autonomous vehicle features will also occur as a result of competitive business agendas rather than a public policy formulation approach. Perhaps we have not fully considered the potential ramifications on existing transportation plans nor the rapidity with which it might occur. The combined effect on the need to develop additional transportation infrastructure will be cumulative as the percentage of vehicles with autonomous features increases and as the features on each vehicle increase.This is not the first time that changes in the vehicle fleet have    effected transportation development. The increase in fleet fuel    efficiency  influenced the ability to fund transportation infrastructure    over a period of several decades and yet there was surprise when    development slowed as a result. The demand for infrastructure did not    decrease just because vehicles could go further on less fuel, there was    just less money to provide for the growth in demand and the  accumulated   deferral of maintenance. 
 
Fuel  efficient vehicles, electric vehicles  and  vehicles operated on  propane, hydrogen and so forth all ‘demand’  highway  capacity to  operate.  Autonomous vehicles, trip matching and  other  converging  technologies could change transportation paradigms to  an even  greater  extent.
 
In 1999 the  annual  meeting of 
It was essentially the  combination of adaptive cruise control, which maintained distances  between vehicles and lane alignment maintained by sensors embedded in  the pavement edges that communicated with the vehicle. While operating  in a controlled environment, it was nevertheless an impressive  demonstration. It was clear that vehicle autonomy would have many  benefits, however the barriers to such technology were considerable.  Potential litigation as a result of equipment failure was high on the  list of barriers identified. The cost to equip the vehicle fleet with  adaptive cruise control and roadways with necessary sensors was seen as  enormously expensive and would likely take decades.  The regulatory  considerations seemed at first insurmountable and questions such as  determining which roadways should allow autonomous vehicle operation,  the human interface requirements and a myriad of other barriers led  policymakers and the industry in general to consider the practical  implementation of autonomous vehicles to be decades away and perhaps not  possible at all.
 
 
What’s changed?
The private sector has continued to develop the facets and features of vehicle autonomy and began to deploy them as commercially available accessories. On a parallel but radically different track, fully autonomous vehicles were developed using visual and other sensors and advanced software. They are already being driven on public highways and streets in normal traffic where highly unpredictable humans (both drivers and other road users) create instantaneous and wildly varying circumstances.Simultaneously, trip matching using smartphone locator technology, online payment software and instantaneous driver/passenger communications began to be deployed.
As these technologies were refined business models were developed and vehicle manufacturers and software developers began to see the business potential of the convergence. Vehicle manufacturers have started to embrace autonomous travel and have set business strategies for introducing autonomous features for the automobile and competition has quickened. Drivers can now choose whether they want adaptive cruise control, lane alignment, crash avoidance or other features and as further deployment of these technologies occurs, the competition between manufacturers will increase. The deployment of autonomous vehicles is becoming more a factor of commercial competition and individual economic choice than that of policy development.
At    the recent 
The   collaborative business potential of automotive  companies, fully   autonomous software and trip matching is difficult to  predict but the   convergence is clearly occurring.
     
 While regulation  may slow the process   it seems unlikely to be a terminal problem;  safety goals and economic   competitiveness are too nationally  significant. After all, other   automotive features that have saved  lives have been the result of   regulation (air bags, seat belts, ABS…)  and increased fuel efficiency   has been partially a result of CAFÉ  standards.
 
 
Infrastructure demands
The question is not when the fully autonomous vehicle will become a reality or not, but how the cumulative introduction of autonomous features and converging technologies will effect transportation plans and the requirement for transportation infrastructure.The difficulty in predicting the need for transportation infrastructure based on demand, at a given price, is the lack of a publicly understoodconnection between demand and price. As with many public services, it is difficult to relate the choice to use publicly-funded transportation with the cost.
This is especially true for transportation since so few consumers of the infrastructure have any idea what it costs to travel on a highway or use a transit service. The one exception is perhaps the tolled highway and perhaps, more tellingly, the resistance to tolling. Even in this environment, the greater the supply (interstates, highways…), the higher the demand.
So how might increasing vehicle autonomy affect the need for transportation infrastructure? It is likely that there will be more people in the average vehicle and that there will be additional vehicle capacity derived from the same transportation infrastructure.
The number of vehicles that can travel safely in a given lane will be impacted by the ability of advanced vehicle controls.
Currently the average safe driver leaves ‘one car length per 10 miles per hour’ between vehicles (at least they have been taught to do so) but the automated (and autonomous) systems can react much faster than humans and can therefore safely travel much closer together.
As a  larger and   larger percentage of the vehicle fleet  becomes capable of  safe travel in   less space, the real capacity of the  roadway  increases. As the demand   for highway infrastructure is  predicated on  the safe traveling distance   under human control and  traffic and  revenue predictions are based on   these assumptions,  highway capacity  manual assumptions will be   increasingly inadequate as  autonomous  features are introduced. A more   immediate consideration is  whether  and to what extent vehicles with   adaptive cruise control  should be  allowed to intermingle with normal,   that is  human-controlled,  vehicles. Should there be restrictions on how   close a  vehicle should  be allowed to travel behind another and how does   one  know whether the  vehicle behind is operated on adaptive cruise   control  or by an  over-zealous human driver?
 
The    average number of persons per vehicle may  change as well. Several    businesses have been established that offer  driver and passenger    matching for car and ride sharing. 
     
There has been  some institutional    resistance as this challenges some long held  business models but the    convenience and economic benefit that can be  derived is leading to    growth in these services. Freedom from the  responsibility or cost of    driving and the opportunity for drivers to  share or fully fund driving    costs could result in more passengers in  each vehicle. Single  occupant   vehicular travel has been a predominant  and enduring pattern  in   transportation but as the convergence of  technologies increases,  this   may at last begin to change. Even a small  percentage increase in  vehicle   occupancy will have a significant  effect on the demand for    transportation infrastructure. This change  will not be immediate, but  it   is likely  
Tipping point
Individual choice of a mode of travel is based on convenience, safety, economics and freedom. The populace is sometimes slow to adopt new technologies but convenient, safe and economical travel is a large factor in the quality of life and as more people in the US become seniors, mobility becomes a major factor in their quality of life. The ability to drive is often synonymous with whether someone can maintain a home without assisted living services or even moving to a rest home. The autonomous vehicle could fundamentally change that dynamic.Equally    the many thousands of lives that are  lost  each year to automobile    accidents could potentially be  eliminated  and the cost of automobile    insurance could be  significantly reduced.  Given the choice of owning an    automobile with  or without accident  avoidance, most people would  select   the enhanced  safety model and  the greater the proportion of  such   vehicles on the  road the greater  the savings in lives, time and  money.
 
Imagine     a largely  autonomous vehicular travel environment.
     
 Commuters no   longer   own  vehicles, the services are ordered up on a smartphone or   similar    device by logging the desired time and place of origin and   the    destination (the quicker the travel time for a given distance,   the    greater the price). The vehicle could be individually owned or   the    property of a transit company, a corporation or a charitable      organisation.
     
 Ownership becomes somewhat irrelevant and such an      environment would create a marketplace that will seek its own level of      supply and demand at a competitive price. For the consumer, travel      becomes more convenient, more cost-effective, safer and quicker. No      longer would an individual be faced with buying a vehicle, insuring it      and then risking bodily harm when driving it. There would be no  need  to    maintain it or park it - so there is no need to worry about  it  being    scratched or dented in the parking lot. There may not even  be a  need  for   a driver’s license.  
 
Where      will the tipping point occur? Perhaps we have already passed it.  The     current state of autonomous vehicle development is probably not  the     issue. It is clear that it is happening and we should dedicate  our     energies to planning for mobility and operating the  transportation     infrastructure to get the most benefit from all  existing assets.
 
Regulation      could be a significant restraint to obtaining this futuristic      autonomous environment but control by regulation will be limited and      temporary. When viewed without barriers to introduction, autonomous      travel is a disruptive technology that will affect both the private and      public sectors. Regulation may be introduced to minimise this     disruption  and smooth the transition but the transformation will     continue. The  private sector and the public sector can compete or they     may support  each other through various public private partnerships    that  focus on  mobility and demand rather than the supply of    infrastructure.  
     
The only certainty is that in the future we won’t be doing things as we are currently and some great opportunities exist! 
     Harold  Worrall is president of consultancy 
    
        
        
        
        



