What if public agencies don't change transportation policies or regulations as autonomous vehicles (AVs) enter the market and expand their presence on American roadways? This is one of many questions we investigate in assessing the potential risks that AVs present to the desired future outcomes that cities, regions and states have established through their land use and transportation plans. We use the term "risks" purposefully. This is because our research and modeling reveal the potential for substantial increases in vehicle travel and decreases in transit ridership if AVs operate under current policy and regulatory frameworks. So, what can policymakers and local agencies do?