| Box Width: | 250 |
| Number: | B Line |
| Titlecolor: | white |
| System: | RapidRide |
| Operator: | King County Metro |
| Garage: | East Base |
| Vehicle: | New Flyer articulated buses |
| Open: | October 1, 2011 |
| Predecessors: | Route 230, 253 |
| Locale: | King County |
| Communities: | Redmond, Overlake, Bellevue |
| Start: | Redmond Transit Center |
| Via: | NE 90th St 148th Ave NE NE 40th St 156th Ave NE NE 8th St |
| End: | Bellevue Transit Center |
| Length: | 10miles |
| Frequency: | Peak: 10 minutes Off-peak: 15 minutes Early morning & night: 30 minutes |
| Alt Frequency: | 15 minutes (most times) |
| Time: | 50 minutes |
| Day: | Weekdays: 4:21 am-12:25 am Weekends: 6:00 am-12:25 am |
| Ridership: | 6,600 (weekday average, spring 2015)[1] |
| Timetable Link: | B Line timetable |
| Map Link: | B Line map |
| Map State: | show |
| Map Name: | Route diagram |
| Previous Line: | A Line |
| Next Line: | C Line |
The B Line is one of seven RapidRide lines (routes with some bus rapid transit features) operated by King County Metro in King County, Washington. The B Line began service on October 1, 2011,[2] running between downtown Redmond, Overlake and downtown Bellevue. The line runs mainly via NE 8th Street, 156th Avenue NE, NE 40th Street and 148th Avenue NE.[3] Unlike most of the RapidRide lines, the B Line does not offer scheduled service during late-night and early morning hours.
This corridor was previously served Metro routes 230 and 253 which carried a combined average of 5,070 riders on weekdays during the last month in service.[4] Since the implementation of RapidRide on the corridor, ridership has grown 30 percent and the B Line served an average of 6,600 riders on weekdays in spring 2015.
| 4:21 am – 6:00 am | 15-30 | No Service | |
| 6:00 am – 9:00 am | 10 | 15 | |
| 9:00 am – 3:00 pm | 15 | 15 | |
| 3:00 pm – 6:00 pm | 10 | 15 | |
| 6:00 pm – 10:00 pm | 15 | 15 | |
| 10:00 pm – 12:25 am | 30 | 30 | |
| 12:25 am – 4:21 am | No Service | No Service |
All times are estimated headways.