Writing Feedback / Two types of transportation: Is Compare and Contrast Clear Enough? [5]

(time / cost / ?) - what will be a good main point for contrast essay

what will be my three main point if i write a contrast essay of transportation?
could it be good if i use like
1. time
2. cost
3. i have no idea for the number three can someone help me with it
it will be a very big thank you.