I don't want my tax money wasted on that. In most urban areas there's simply no space for separate autonomous vehicles roads. Would rather see that money spent on maintaining existing roads and improving schools.
That doesn't mean I don't want any roads for private vehicles. Just that need not make up 99% of them. Even if we knocked that down to 75% of roads I think we'd see amazing positive impacts on every metric (except the private roads; those will continue to suffer from congestion until cities offer a better way to get people from A to B).