Complex sentence: By March 1970, the original section between Home Avenue and near I-8 was almost complete, and the Mission Valley portion extending north of US 395 as well as from Otay Valley Road and J Street in Chula Vista were still under construction.
Split into simpler sentences: By March 1970, the original section between Home Avenue and near I-8 was almost finished. The Mission Valley portion extending north of US 395, as well as from Otay Valley Road and J Street in Chula Vista, were still under construction.