Technology

Yes, I have no doubt there would be induced demand, but that extra demand wouldn’t be at the cost of anything.

But if AVs add more capacity to our roads, that will be entirely because they are driving more efficiently.

you are literally doing what i mean when i say you are making assumptions with no evidence. there is, again, no reason to believe that "driving more efficiently" will result from mass-adoption of automated vehicles--and even granting they do, your assumption that this wouldn't be gobbled up by induced demand is intuitively disprovable. even the argumentation here parallels other cases where induced demand happens! "build[ing] new roads or widen[ing] existing ones" is a measure that is almost always justified by an underlying belief that we need to improve efficiency and productivity in existing traffic flows,[^1] and obviously traffic flow does not improve in such cases.

but granting that you're correct on all of that somehow: more efficiency (and less congestion) would be worse than inducing demand. "efficiency" in the case of traffic means more traffic flow at faster speeds, which is less safe for everyone—not more.[^2] in general: people drive faster, more recklessly, and less attentively when you give them more space to work with (especially on open roadways with no calming measures like freeways, which are the sorts of roads autonomous vehicles seem to do best on). there is no reason to believe they would do this better in an autonomous vehicle, which if anything incentivizes many of those behaviors by giving people a false sense of security (in part because of advertising and overhyping to that end!).

You’re asking for something that does not exist. How am I supposed to provide you evidence proving what the results of mass adoption of AVs will be when there has never been a mass adoption of AVs.

you asserted these as "other secondary effects to AVs"--i'm not sure why you would do that and then be surprised when people challenge your assertion. but i'm glad we agree: these don't exist, and they're not benefits of mass adoption nor would they likely occur in a mass adoption scenario.

For instance, what is your reasoning for believing that AVs could never be fundamentally safer than human drivers who are frequently tired, angry, distracted, impaired, impatient, etc?

the vast majority of road safety is a product of engineering and not a product of human driving ability, what car you drive or its capabilities, or other variables of that nature. almost all of the problems with, for example, American roadways are design problems that incentivize unsafe behaviors in the first place (and as a result inform everything from the ubiquity of speeding to downstream consumer preferences in cars). to put it bluntly: you cannot and will not fix road safety through automated vehicles, doubly so with your specific touted advantages in this conversation. the road designs that create bad driving behavior don't cease to be an issue because people switch to an automated vehicle.

[^1]: take for instance “Tackling Traffic Congestion,” Transportation Quarterly 40, no. 2 (1986), which states "growing congestion [in the Bay Area] [...] is the result of development that comes with an improving economy compounded by a lagging expansion of freeway and transit capacity." [^2]: see for instance Leonard Evans, “Future Predictions and Traffic Safety Research,” Transportation Quarterly 47, no. 1 (1993): “although congestion impedes mobility, it increases safety, as measured by serious injuries and fatalities.” and Arnold Vey, “Relationship between Daily Traffic and Accident Rates,” American City 52, no. 9 (1937), who observed that beyond a certain point congestion reduced accident rates. congestion unsurprisingly acts as a calming measure when it becomes severe enough.