Preparing Your Agency for Transportation’s Autonomous Future
Article

The Future is Here: Get Ready for Autonomous Transportation

This article was originally published in the June 2018 APWA Reporter. Special thanks to the American Public Works Association for permission to reprint the full article.

Introduction

Autonomous and connected vehicle (AV/CV) technology is rapidly evolving for both personal vehicles and transit applications while new mobility business models emerge. Public agencies are challenged with developing a framework that will support and manage private investment and opportunity while evolving their own set of public services.  What’s lacking is a firm understanding of the role that public sector agencies should have to both drive the evolution and to be ready for its impacts. This article addresses these issues and offers examples of how some agencies are preparing for the rapid changes coming our way.

  • With technology developing so rapidly, how can public agencies make informed decisions on where and how to most effectively devote public resources and investments to support personal AV/CV adoption?
  • How can transit agencies incorporate emerging technologies to become more efficient, safe and equitable?

Personal AV/CV Adoption

Autonomous vehicles will radically change the travel patterns, vehicle behavior and ultimately the infrastructure needed for safe and efficient travel. Numerous literature sources have made predictions about potential adoption rates. As shown in the chart in Figure 1, there remains considerable uncertainty in the coming decades: the AV penetration in the year 2030 ranges from 10 percent to 40 percent, and in 2040 the range is even wider, at 20 percent to 85 percent. While our future is never certain, there are steps public agencies can take to make investments today that balance immediate needs with the flexibility necessary to meet the needs of tomorrow. This activity is frequently referred to as “future-proofing” an agency’s programs, policies, procedures and investments for prospective technology.

Figure 1. Range of Potential AV Adoption Rates

Travel Demand Scenario Planning

New technologies and travel options coupled with shifting user preferences require a new approach to long-range transportation planning. The Florida Department of Transportation (FDOT) is starting to use a next-generation scenario planning tool called “TransFuture” to account for trends in AV adoption, societal changes and travel behavior. TransFuture allows users to define scenarios within regional travel demand models based on variables such as generational travel behavior, AV adoption and shared mobility usage. The output displays probabilistic results and confidence intervals for factors such as annual average daily traffic (AADT) and vehicle miles travelled (VMT). Figure 2 shows the variables considered in building a hypothetical scenario (in this case AV adoption rates), while Figure 3 shows the associated impacts on congestion and safety compared to the baseline.

Figure 2. Setting Autonomous Vehicle Adoption Rates for a Travel Demand Scenario in TransFuture
Figure 3. Example of TransFuture Monte-Carlo Simulation Results for a Roadway Segment from a Congestion and Crashes Scenario

Microsimulation

Tools like TransFuture can help agencies make more informed facility expansion decisions, but agencies still must validate the impact emerging transportation technologies will have on the facilities’ operating conditions. One possible approach for incorporating AV/CV adoption and societal trends for operational analysis is through the use of microsimulation modeling. With microsimulation modeling, the behavior of autonomously driven vehicles can be modeled as a function of various penetration rates. Reduced headways, harmonized speeds and avoidance of speed shockwaves can all be modeled. For example, as part of the Interstate 80 Planning and Environmental Linkages Study, Iowa DOT customized its microsimulation models to account for AV/CV characteristics such as reduced headways, a lower distribution of driving speeds and the ability to form multi-vehicle platoons. A range of AV adoption rates were applied to determine the resulting impact on vehicle throughput. Figure 4 compares 2040 scenarios to existing conditions for a rural segment of I-80 in Iowa. Based on this finding, it was determined that high levels of AV adoption could delay the need for additional Interstate 80 expansion by 20 to 30 years or more when compared to standard analyses that omit the impacts of AVs. 

The demonstrated safety benefits were also considerable.  It is estimated that about 90 percent of crashes are caused by human error, which even low-level autonomous safety systems can help reduce.  As shown in Figure 4, the addition of new capacity and AV safety technology to the unimproved scenario in 2040 is predicted to decrease crashes per mile by 59 percent, with fatal and serious injury crashes cut in half. Importantly, these numbers still reflect the doubling of traffic volume associated with the addition of a lane and the capacity benefits of AV technology.

Figure 4. Summary 2040 Scenarios versus Existing Conditions on I-80 in Iowa

Roadmapping

With considerable uncertainty in AV adoption rates as shown in Figure 1, it can be difficult for agencies to plan their investment strategies. . Whether we see a conservative or aggressive rollout of AVs, agencies can establish roadmaps to characterize facility needs at certain adoption thresholds. Figure 5 shows the middle ground in adoption of AV/CV technologies, with a corresponding technology roadmap that includes the following key steps:

  • Today: Include AV/CV considerations in project planning and prioritization
  • 2020: Equip facilities with infrastructure-based CV equipment and determine the appropriate pavement marking and reference points for early AV adopters.
  • 2030: Prioritize construction of dedicated AV lanes on highways.
  • 2040: Provide additional dedicated AV lanes in response to market demand.
  • 2050: Equip highways with smart pavement that can dynamically shift lane uses and restrictions based on real-time conditions.

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Figure 5. Example of Market-Responsive Transportation Technology Insertion

Transit AV Adoption

Many transit agencies will find that infrastructure future-proofing strategies are similar to public transportation agency planning for incorporating personally owned AVs. Transit authorities can also adopt strategies to help prepare themselves to be autonomous transit vehicle owners and operators. Figure 6 illustrates areas where agencies are planning or already operating pilot projects to determine AV infrastructure needs, evaluate AV microshuttle performance and provide an opportunity for the public to interact with the technology firsthand.

AV adoption in the transit sector could take numerous forms, from full-size AV buses serving high-capacity routes to microshuttle vehicles that act as first- and last-mile circulators. One potential early adoption of AVs in the transit environment is with “microshuttle” vehicles. These vehicles are smaller 12-15 passenger vehicles that operate at low speed and can navigate fixed routes autonomously. These AV microshuttles have enjoyed high visibility at recent industry conferences and limited-scale demonstrations.

Figure 6. Summary of Autonomous Micro-Transit Vehicle Deployments in the U.S. in 2017

Understanding AV Microshuttle Capabilities

The Jacksonville Transportation Authority (JTA) plans to use AVs to modernize and expand its Skyway people mover as part of its Ultimate Urban Circulator (U2C) vision. In support of this effort, JTA recently opened an AV test track where it will rotate through vehicles from different manufacturers to test a range of sizes, speeds and capabilities. In designing its test track, JTA considered factors such as remote vehicle monitoring, traffic signal technology, pavement marking and station design to create an AV-friendly environment. Additionally, a concept of operations was developed to describe how AV microshuttles should respond to a range of possible scenarios.

Incorporating AV Microshuttles into Existing Transit Systems

The City of Lincoln, Nebraska, recently kicked off the planning phase to deploy four autonomous microshuttles into a mixed-traffic scenario on public roads. It is one of the most ambitious AV transit projects in the country. This two-year pilot will establish a fully operational service open to the public to help the Lincoln community become familiar with AV microshuttles, and to allow city officials to evaluate how these vehicles can be incorporated into a transit system at a larger scale. The proposed system will be demand-responsive, meaning shuttles will be deployed dynamically along a fixed route based on the origins and destinations of passengers. Riders will be able to request pick-up and drop-off locations from a smartphone app. The pilot is intended to combine the fixed route and stops of traditional transit with the ease of use that comes with a ride-hailing service.

Partnering with Transportation Network Companies

Seattle-area municipalities and Sound Transit recently partnered with Uber to encourage commuters to use alternative transportation and reduce the number of people driving to work. Uber is offering discounted rides to riders traveling to and from eight light rail stations south of Downtown Seattle. This partnership is intended to fill transportation gaps that make it difficult for some people in the region to use transit. While the promotion is temporary, it provides a good model for public agencies to consider in addressing first- and last-mile transportation challenges.

Summary

It’s not too soon for roadway owners and operators to begin incorporating projected AV/CV adoption rates and societal trends into their travel demand and microsimulation models.   By doing so, they can avoid over-investing in new capacity or under-investing in infrastructure-based technology. Similarly, transit agencies should begin considering the implications of owning and operating AV transit vehicles. The good news is there are numerous examples of agencies that have already launched successful efforts aimed at achieving these objectives.

These emerging technologies will also enhance the data available to agencies and present the opportunity to respond more directly to the unique user needs of their communities. By understanding the capabilities and market penetration of AV/CV technology at the global scale, and combining this knowledge with their own local conditions and user needs, public agencies can shift their approach to transportation from a problem to be solved to a solution for solving societal problems. Ultimately, the mandate of public agencies is to provide their communities safe, efficient and equal access to mobility. By adopting emerging technology, agencies will be able to meet this mandate in new and better ways.

Project Manager, Transportation Technology
Automated and Connected Vehicle Transportation Planner
Transportation Technology Program Lead
Director, Highways & Roads