As I said in Part 1, I'll compare the differences between Space Individualized Transit (SIT), Individual Mass Transit (IMT) and RUF. PRT (Personal Rapid Transit) is an effort to add flexibility back to public transportation systems, and thus increase their use.
Conventional PRT makes progress, but it still misses the final mile. Sometimes I look forward to a walk, but there are many instances where it's a problem. Also, not everyone thinks like I do. Bad weather and time are downers for almost everyone, myself included. In addition, 35lb bags of dog food or furniture are more than just inconveniences. Thus with conventional PRT, conventional rail or buses the need for conventional roads remains. Those costs, being rather large, will always hold back secondary transportation methods.
IMT and RUF however interface with conventional roads and make to your door delivery a reality. While that doesn't reclaim the costs of roads, it does make IMT and RUF viable replacements for 100% of needs. Once you have a guideway and a vehicles capable of using it, there is no reason not to. Guideways are thus no more secondary than highways are today.
SIT provides the same capabilities since compartment can be placed on drive-by-wire sleds in non-automated environments. Operators can then use controls inside the compartment to drive like any other car.
Since SIT's is multi-modal, compartments can interface with conventional rail, long distance mag-lev tracks or Evacuated Tube Transport. In addition, conventional rail or light rail can provide mid range travel to reduce initial infrastructure costs.