I too have been trying to work out what 'extra' travel assist gives you over predictive active cruise control. Pressing the travel assist button on my 71 Karoq makes the green lane control light on the dashboard to off and the central lane recognition display develops two orange lines. The only 'extra' I have noticed is that the steering automatically keeps you in lane. However, the system complains after about 10 seconds if there is no driver input even in a crawling traffic jam. I haven't been able to find much documentation about how the travel assist / traffic jam assist systems are supposed to work. Does anybody know for definite what these systems should do?
