Traffic Jam Assist?

No. The 'it' I said that you don't have is Predictive EV Drive, one of the three possible subfunctions collectively grouped under 'predictive efficient drive'.

You should read that thread more carefully; you seem to have skimmed it.

This is the important clarifying post.

Part of the confusion is that the US car only has one of the three functions, so it's not clear in the cut-down manual what the distinction is supposed to be between 'predictive efficient drive' and 'predictive deceleration support'.

 

It differs from what the system does in Europe.
"For one, it doesn't include the geofencing feature to identify the densest urban areas that might best be electric-only. And in the U.S., the system doesn't draw from crowdsourced information or a deeper layer of map data, other than live traffic data.

Instead, the car itself is gaining route-specific information about your driving. That learning is "kept local on the vehicle and is not shared outside the car or stored on the cloud," according to Toyota. And while some efficiency-based systems—such as those from Audi—draw from terrain data embedded in maps, Toyota's Predictive Efficient Drive is primarily studying the drive force and road load."
Will Toyota Prius Prime gain EV route planning smarts?

The US version sounds like the EV+ mode on Ford Energis with the addition of live traffic input.