Complex sentence: The interchange between I-5 and SR 18 is being reconstructed in Federal Way, with a new flyover ramp from westbound SR 18 to SR 161 being completed in September 2012 and another ramp, from southbound I-5 to SR 161, is under construction.
Split into simpler sentences: The interchange between I-5 and SR 18 is being reconstructed in Federal Way, with a new flyover ramp from westbound SR 18 to SR 161 being completed in September 2012. Another ramp, from southbound I-5 to SR 161, is under construction.