Powered activator rails will eject any mobs from the minecart (passive or hostile), it's what they are used for. I used one when transporting a large number of villagers from my base to a village about 500 blocks away so I didn't have to worry about babysitting the minecarts all the time.
Activator rails kick the cart occupant to any open spot around the cart. If you are delivering the villager to a specific spot, you want to block off the other options.
In my world, I was delivering villagers to another village I had built. I wanted them delivered to specific houses, so I fenced in the door of each house. I put the redstone block in the ground just outside the open gate. I then laid the activator rail on top and connected it. I put trapdoors on every spot around the activator rail, except the open gate. Then the villager would be kicked out into the gate and could not escape. Once the villager moved out of the gate, I closed it and he was home safe. Here's a picture of it.