Complex sentence: This may mean that there is not enough 220 MHz PTC radio equipment available for all 42 railroads that must implement PTC and in that case, 220 MHz may actually be a poor choice if there is no other reason to justify using it.
Split into simpler sentences: This may mean that there is not enough 220 MHz PTC radio equipment available for all of the railroads that must implement. In that case, 220 MHz may actually be a poor choice if there is no other reason to justify using it.