Route 427 provides local East-West service between Spring Hill Metro Station and the Farm Credit Administration. The route travels primarily along the Jones Branch Drive and Dolley Madison Boulevard corridors. Please note that the bus enters the McLean Metro Station in the eastbound direction only.

Popular locations along the route include:

• McLean Metro Station (in eastbound direction only)
• Freddie Mac HQ 2
• Farm Credit Administration
• McLean Governmental Center
• MITRE HQ
• Capital One HQ