Staying patient is the key to managing traffic jams in Myrtle Beach.   Also, it helps to avoid certain areas during certain times of day. Don't head south on the Route 17 bypass between the hours of 4 and 6pm as it can be a nightmare with locals heading home from work.  
Ocean Boulevard is a cruisers heaven at night so unless cruising is your plan you should avoid the boulevard between 25th Ave. north and 10th Ave. south and use Kings Highway or Grissom Parkway instead.

Route 501 coming into the beach can backup as far out as Conway (20 miles from the beach) so you may want to take Route 22 (just past Aynor) to Route 31, to Grissom Parkway to get to the beach.

** Note:  The original information for this thread came from the following forum thread: