TJA vs LKA

[NLMGSAN]

TJA uses both camera and radar. If the camera provides insufficient information about lane markers, it goes into 'follow mode'.
LKA uses the camera as well. How come in TJA mode the camera shows lane markers, but on the same road (with double solid markers) LKA cannot?

 

[siteguru]

In my car, TJA is only active a) when cruise control has been turned on, and b) when the car can see lane markers on both sides of the lane. Without cruise control, if I look at the driver display I can see the steering wheel symbol (for TJA) going grey when only 1 lane marker is detected, and white when both are detected. With TJA in operation (active) then the symbol goes green rather than white.

LKA functions even when only 1 lane marker is detected, but will obviously only warn/correct steering if the car veers towards that marker.

With LKA the lane markers switch between solid and dashed depending on the type of lane marker on each side; with TJA the markers are green when active, and sold/dashed (as applicable) when not.

(The above is all from memory).