They saw the freeway and thought it was the runway as I recall. They
got off the gauges too soon. A mistake most of us have made at least
once in our career (not the aiming for the highway part, the getting
off the gauges too soon part). For part 135 IFR operations one pilot is
required to stay on the guages while the other pilot is allowed to look
outside for a positive ID on the airport. Not a good thing when both
start looking outside.

-Robert