What capability did Potts' timed, interconnected system enable that independent, non-communicating signals could not?

Answer

Engineering traffic patterns across several blocks simultaneously via 'green waves.'

The interconnected timing allowed traffic patterns to be engineered across several blocks simultaneously, a capability impossible with remote manual control or independent signals.

What capability did Potts' timed, interconnected system enable that independent, non-communicating signals could not?
inventionHistoryautomationtransporttraffic light