Autonomous Vehicles. Clifford Winston

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      Introduction

      Transportation innovations and investments have contributed significantly to U.S. economic growth. They have enabled households to optimize their residential and workplace locations and their choice of employers; encouraged firms to increase the size and scope of their markets, reduce their inventories, and expand their choice of workers; and allowed consumers to benefit from greater competition among domestic and international firms and from more product variety. The motor vehicle, which has contributed greatly to those socially desirable activities, has been listed among the greatest human inventions of all time (Bowler 2017; Winston 2010).

      The increasing dominance of cars and trucks for transporting passengers and freight has evolved with the development of the U.S. public road system, which represents the nation’s largest civilian public investment and has become the arterial network of the U.S. economy. Today, some 90 percent of commuters use cars to get to work, 70 percent of travelers use cars for intercity trips, and 30 percent of shippers of intercity freight (measured in ton-miles) and nearly all of their urban freight is shipped by truck—all of those movements rely on a federal-highway capital stock that is valued at roughly $3 trillion (Winston 2013).1

      Given the importance for the U.S. economy of motor-vehicle transportation and the infrastructure that it uses, significant changes in the performance of either could have a large effect on economic growth. To date, however, the road network has been characterized by growing traffic congestion, deteriorating pavement, crumbling bridges, and a staggering number of crashes. The annual cost of congestion, vehicle damage, and injuries and fatalities runs in the trillions of dollars.

      Some economists have argued that the decades-long underfunding of highway infrastructure is the cause of those problems. They have called for policymakers to increase expenditures to repair pavement, renovate bridges, build new roads, and modernize signaling.2 Other economists have highlighted the inefficiencies in government highway pricing and investment policy, arguing that the public sector has wasted hundreds of billions of dollars by failing to charge road users for their contribution to congestion and their damage to pavement and bridges and by neglecting to make investments that maximize social benefits.3

      Those calls for reform have largely gone unanswered. Federal efforts to improve our nation’s highway system have stalled for decades. Although nineteen states have raised their gasoline taxes since 2015, they have done so only because improvements in the fuel economy of the nation’s automobile fleet—together with a federal gasoline