Statements about the effects automated technology will have on infrastructure are often punctuated by question marks. How will autonomous vehicles (AVs) change the transportation landscape? How will they impact travel levels — or, more importantly, safety? And how quickly and completely will the technology be adopted?

With so many questions unanswered, the transformational impacts of AVs remain a mystery for many agencies. 

Iowa DOT took a holistic approach when evaluating these impacts on infrastructure planning and design as part of its statewide Interstate 80 Planning Study. We completed all aspects of the study’s Technical Memorandum on Automated Corridors, which evaluated scenarios ranging from rapid, high-level AV adoption, to partial and gradual adoption, from now to the design year and beyond.

Goals for the study included: 

• Leverage existing AV knowledge
• Help the agency understand AVs and other transformative shifts in transportation
• Prepare for AV impacts on safety, mobility and reliability in Iowa
• Consider the effect of AVs on future I-80 design
• Communicate to the public the impact of AVs

We used scenario planning, predictive safety analysis and customized traffic-capacity simulation to identify large potential benefits for travelers if AVs are aggressively adopted. Our thought leaders in transportation technology devised a data-driven, research-based approach to help Iowa DOT measure the range of potential AV impacts in meaningful ways — the practical upshot of which is better-informed planning and design decisions. That includes a new perspective on expandability needs beyond the design year. 

The study's findings allowed Iowa DOT to broadly consider “future proofing” in the design of I-80, including provisions for: continuous power and communication along the corridor; detection and data processing of AV information; enhancements to pavement structures to accommodate increased traffic demand due to AVs; and accommodation of expandability, including future AV-only lanes. 

A communications plan developed by our public involvement team helped, and continues to help, Iowa DOT explain to a general audience the impact AVs will have on I-80. The communications plan included development of an educational video that clearly explains AV technologies and their impacts on infrastructure and the traveling public. The video included 3-D visualization of the traffic simulation and explained Iowa’s approach to accommodating new transportation technologies.