The distances are measured in cable length, not as the crow flies. Generally the cable connecting a customer to a Central Office does not run in a straight line. Instead, the cable twists and turns underground so the distance measured in cable feet is always longer than the distance measured as the crow flies. In the U.S around 20 percent of local loops have devices called loading coils installed to increase inductance. They carry voice signals further and improve the quality of the voice service, but cause distortion at the higher frequencies used to carry digital information.
Most telephone companies have a process where the loading coil is removed from the line.
A bridged tap is an accidental connection of another loop to the primary loop. It could be an unused copper pair at an intermediate point or an extension of the circuit beyond the service user location. Each bridged tap introduces signal attenuation. In all, the average U.S local loop has 22 splices in it which adds up to a lot of signal attenuation. Generally speaking, the length of the bridged tap determines the level of signal attenuation.