What is the reason that Bus resistance is normally small
Unless designed otherwise, logic drivers aren't very strong. The process of transmitting a signal can be modelled as charging a small capacitor (a few pf) on the device to be driven, through the resistance of the bus. The higher the resistance, the slower the rise time on the target.

For slow signals you can go up to a few hundred ohms, or insert 100 ohm resistors in a bus if you fear it may be accidentally driven from both ends.

11 ohms seems quite high for a PCB trace.