Bridgton has no train or bus service to speak of, and a car is essentially required. The nearest commercial airport is Portland International Jetport (PWM), about 45 minutes southeast on Route 302. Boston's Logan Airport is roughly 2.5 hours south.
From Portland, take Route 302 west — it runs directly through Bridgton's Main Street. From the White Mountains, take Route 302 east from North Conway, New Hampshire (about an hour's drive). From the Maine Turnpike (I-95), exit at Gray or Westbrook and follow Route 302 west.
Parking in town is free and easy to find outside of peak summer weekends.