Collision with zero thickness. Is this possible?

Hi. I’m working on a maze game where the pathways are one tile wide and are separated from another pathways with a thin wall.

Here’s the quick example of the situation: http://imgur.com/m9fC8E2

The tile is 16x16 and the character is 16x16. Is there a way to set the collision of those thin walls so 16x16 character will fit into the pathway but will be stopped once he reaches the wall?
Right now if I use a rectangle to set the collision of those wall tiles (tiles 3, 4, 5 etc.) players stops 1 pixel earlier than I want.

You could try a polyline instead of a rectangle, but you’ll probably run into the same problem. This is because there will be some inaccuracy in the physics engine. You could probably solve it by using a 15x15 character instead.

Alternatively, you could write your own collision logic. Your example does not seem that much in need of a physics engine as it is.