Friday will be one of worst days, unfortunately.

For Inter. flights, you'll like have to be at LAX by 1:30 or so. It will take you about 3-3 1/2 hours from SD to LAX at that time of day...could be more or a bit less.

You might wish to avoid Interstate 405 between Long Beach and LAX since it always seems to be the worst. Once you connect with the I-405 in Orange County (it'll be the I-5 from SD to OC), then you might consider taking the I-605 north to the I-105 and then taking the I-105 west to LAX. It may be less of a problem. It sounds more complicated than it really is...take a look at a map and you'll see it's pretty straight forward and the 605 and 105 tend to be less congested than the 405 (which I try to avoid like the plague).

The other alternative is to leave SD first thing to try to avoid the afternoon traffic crunch, get close to LAX and stop off for lunch along the beach...Redondo Beach, Manhattan Beach, Venice, etc. which are all within 20 minutes or so of LAX.

Email back if you have any other questions.