Is LTA different from LKA (Lane Keeping Assist)?
Apparently, yes. What I think are good sources of information are PDF documents linked from the Lexus USA consumer site that explain
Lexus Safety System+ and
Lexus Safety System+ 2.0
From the former:
LANE DEPARTURE ALERT with STEERING ASSIST and LANE KEEP ASSIST
Standard: GS 2016-9 / GS F 2016-19 / LS 2018 / RX 2016-9 / LC 2018-19
This system is only a driver assist function, and will deactivate when the driver is not holding the steering wheel and steering.
- The system assists the driver with some of the steering operations necessary for staying in the current visibly marked lane while the
Dynamic Radar Cruise Control* is on.
- Using the DISP switch on the steering wheel, the Lane Center Assist for the Lane Keep Assist can be activated or deactivated on the customization display of the Multi- information Display.
* When Dynamic Radar Cruise Control is not in operation, the Lane Keep Assist function does not operate either.
And the latter:
LANE TRACING ASSIST
Availability: LS 2019 | ES 2019 | UX 2019
Lane Tracing Assist is designed to work with Dynamic Radar Cruise Control to keep the vehicle centered in its visibly marked lane and preemptively avoid unintented lane departures.
Lane Tracing Assist uses a forward-facing camera to monitor lane markings – as well as the path of the vehicle ahead, if needed – and is designed to automatically make constant steering inputs to help keep the vehicle centered in its lane. Lane Tracing Assist requires the driver's hands to remain on the steering wheel.