Somes time of day are worse than others. Leave before 7 am and you'll be in SM 20th & Colorado in 25 minutes. Leave at 8 :30 and figure 50 minutes. Worst comes to worst, sit in traffic while enjoying a spectacular view (canyon and ocean).
Frankly the "night life" is kinda lame. Once you're up here for a while, you'll make friends. Most of the "in-canyon" social scean revolves around house parties, pool parties, bbqs. It great community for young folks with young kids. Topanga is DOG HEAVEN!!!