Interstate 275 heads west from Tampa across Tampa Bay to St. Petersburg, swings south, and crosses the bay again on its way to Terra Ceia, near Bradenton. U.S. 19 is St. Petersburg's major north–south artery; traffic can be heavy, and there are many lights, so try to avoid it. Alternatives include 66th and 4th streets. One key thing to remember about St. Pete is that the roads form an easy-to-navigate grid: streets run north to south; avenues run east to west. Central Avenue connects downtown to the beaches.
Around St. Petersburg, Pinellas Suncoast Transit Authority serves Pinellas County. Look for buses that cover the beaches and downtown exclusively.
St. Petersburg Trolley will get you to key destinations throughout downtown St. Pete, and even offers free service between the Chamber of Commerce Visitor's Bureau and certain destinations.
Pinellas Suncoast Transit Authority (727/540–1800. www.psta.net.)
St. Petersburg Trolley (727/821–5166. www.stpetetrolley.com.)