Iowa DOT estimates that AV adoption could increase freeway lane capacity up to 26 percent on I-80.

A micro-simulation model (VISSIM) was used to estimate the impacts of automated vehicles (AV) across a range of adoption rates.

Date Posted

Interstate 80 Automated Corridor

Summary Information

The Iowa Department of Transportation performed an analysis to understand the future of automated vehicle (AV) adoption, and how such vehicles may be accounted for in the agency’s vision of the I-80 corridor. Researchers examined a range of scenarios for future AV adoption rates and considered how the benefits of AVs could be incorporated into future-facing designs for I-80. The overall intent was to allow the design to be flexible for a broad range of potential AV futures, while still meeting the corridor's needs in the present day. The researchers also performed analyses of how traffic capacity, road safety, and travel time would be affected by different proportions of AV adoption. The analyses were performed using a VISSIM traffic micro-simulation model, incorporating both the specific patterns of the I-80 corridor and the particular abilities enabled by V2I technologies.


At a 85 percent AV adoption rate, the capacity of a single freeway lane was projected to raise by 26 percent, to 3,000 vehicles per hour. Additionally, the demand-to-capacity ratio was found to significantly decrease to 0.51 for eastbound lanes and 0.45 for westbound lanes, compared to the current ratios of 0.65 and 0.58, respectively.