Complex sentence: At the time, the Pennsylvania Turnpike ended in a cornfield, with traffic following a temporary ramp onto rural local roads leading into small towns in Ohio, until the connecting Ohio Turnpike could be built.
Split into simpler sentences: At the time, the Pennsylvania Turnpike ended in a cornfield. Traffic followed a temporary ramp onto rural local roads leading into small towns in Ohio until the connecting Ohio Turnpike could be built.