I would say traffic is down somewhat but partially its due to school being out for the summer. I drive the 56 daily at 730am and its still packed every day. Its lighter due to schools being out. I also take it at 5-6 each evening and it backs up daily.
Unfortunately thats only one road. Try the 805 south from the 5 split in Sorrento at 5pm any weekday and let me know how it is.
Take the 15 south at the same time from mira mesa.