Darien can be accessed through three main roads: I-95 North, the Merritt Parkway, and Post Road (also known as Boston Post Road or Route 1). Since traffic to/from New York City is heavy, the best and worst times to drive are: 

Best: 

In the mornings, driving north

In the afternoons, heading south

Worst: 

In the mornings, driving south

In the afternoons, heading north

DMV

The nearest DMV is located in Norwalk at 540 Main Ave, Norwalk, CT 06851. It is closed on Mondays. Since there are so few DMVs in the area, wait times can be hours long. However, once you have your Connecticut drivers' license or ID card, you can renew it at AAA offices which is quick and easy to do.