Sound Transit recently rolled out double-decker buses in a regional partnership along the I-405 corridor.

The new buses will run along Sound Transit routes 532 and 535, which include stops in Bothell, Kirkland and end in Bellevue. They’ll replace the 60-foot long articulated buses, fitting more riders and offering a view high above traffic.

“More seats and more room mean more comfort for transit riders in Bellevue,” Bellevue Mayor John Chelminiak said. “We appreciate Sound Transit’s efforts to increase the capacity of commuter routes, especially as our region continues to deal with congestion.”

Sound Transit maintains an operational partnership with Community Transit, which is the only agency in the region with facilities to maintain and operate double-decker busses. Originally introduced throughout Snohomish County in 2014, the Sound Transit double-decker fleet now includes 37 busses.

The double-decker buses can seat 77 passengers with an overall capacity of 120, compared to an articulated bus with a seat capacity of 59 and a 90-passenger overall capacity.

“Community Transit has a fleet of 70 double decker buses, which we call ‘double talls.’ We also operate approximately 37 Sound Transit double-decker buses,” said Martin Manguia, spokesperson for Community Transit. “Together, that makes 107 double-deckers in service in the Puget Sound area. This is the second largest double decker fleet in the U.S., after Las Vegas.”

While the double talls offer more seating for the same footprint and about the same fuel economy as the articulated buses they are replacing, there are some complications in bus routing. Sound Transit has had to work closely with Eastside cities to “prune” the routes and ensure the 14.5-foot tall buses have enough clearance throughout the stops.

“Roads with low bridge clearances are off-limits. Once we identified corridors we wanted the buses to run on, we had to contact local jurisdictions to see if they would trim trees along those roads,” Manguia said. “Sometimes the answer is ‘yes,’ sometimes it is ‘no.’ Sometimes a yes has a lengthy timeline, as in the case in the Bellevue area.”

Additionally, double-deckers present a cost-related obstacle, costing more than an articulated bus and requiring base modifications to house and maintain the vehicles. According to Manguia, the base-upgrades cost about $6 million, which was partially shared with Sound Transit.

The buses were officially implemented along the I-405 corridor at the end of March and according to Sound Transit spokesperson, Rachelle Cunningham, the rider response has been positive.

“When we introduce them into our routes, people are super excited about them,” Cunningham said. “The view from up top is spectacular, especially in our region.”