There are three external factors that influence the resistance in a conductor. The fourth factor is the conductivity of the material we are using.
Some metals are just more electrically conductive than others.
This however, is considered an internal factor rather than an external one. If the hall is very wide, it will allow a high current through it, while a narrow hall would be difficult to get through due to it's restriction to a high rate of flow. Notice that the electrons seem to be moving at the same speed in each one but there are many more electrons in the larger wire. This results in a larger current which leads us to say that the resistance is less in a wire with a larger cross sectional area. The length of a conductor is similar to the length of a hallway.