Driveway Flare properties

brand new user, and cannot get radius/flare on driveway to show up as an option to change...hover like in the training video, but no "X" ever pops up in order to give option. Select the driveway, click properties, but nothing about entrance or exit flares. What obvious thing am I doing wrong or missing? I hate even asking this, as I am sure it is a no brainer answer.