Complex sentence: Eastgate is at exit 11-A along I-90 which flows east-west along it's north side with Issaquah to the east and I-405 a short distance to the west.
Split into simpler sentences: Eastgate is at exit 11-A along I-90, which flows east-west along Eastgate's north side. Issaquah is to the east along I-90 and I-405 is a short distance to the west.