What are the shuttle wait times and pick-up locations for the SeaTac Rental Car Facility, and how do they differ during peak and off-peak hours?

The Seattle-Tacoma International Airport (SEA) operates a consolidated Rental Car Facility located at 3150 S 160th St, SeaTac, WA 98188. Access to this off-airport facility is exclusively provided by a 24/7 shuttle bus service. Passengers must navigate to one of two designated terminal pick-up islands to board these shuttles: Island 1, located at the extreme south end of the main terminal baggage claim level, and Island 16, located at the extreme north end. These are the only authorized pick-up points; shuttles do not stop at any other islands on the arrivals drive. Wait times are strictly governed by two distinct timing bands. During standard off-peak operational hours, the fleet is managed to maintain a consistent headway of 5 to 8 minutes. However, during high-volume periods, specifically defined as peak morning arrivals (typically 9:00 AM to 11:00 AM) and the Friday afternoon/evening rush (12:00 PM to 6:00 PM), the system experiences significant congestion. During these peak windows, particularly on Fridays when leisure and business travel converge, wait times can extend up to 18 minutes. This delay is caused by increased traffic on the airport drives and higher passenger volume loading at the islands. Passengers are advised to check the digital display boards at the islands for real-time arrival estimates and to ensure they board the correct 'Rental Car Center' branded bus, as other hotel and parking shuttles utilize the same islands.