A line 4 extension would go a long way.
Example, let's say I wanna go to Scarborough city center, and I'm coming from Vaughn, the current option for me is to go down to Eglinton west and then take line 5 to Kennedy, then board line 2 and go up north to my destination.
Now that's quite the distance travelled, but what if, line 4 went to Sheppard west, and took it to Scarborough city center skipping line 5 altogether.
Its not the most needed thing right now but it would definitely allow riders to have more options to get from A to B.
let me know what you think.