The Bx23 and Q50 bus routes constitute a public transit corridor in New York City, running from the Flushing neighborhood in Queens to the Pelham Bay and Co-op City neighborhoods in the Bronx. The Bx23 provides local service in Pelham Bay and Co-op City, while the Q50 provides limited-stop service between Co-op City and subway hubs in Pelham Bay and Flushing. Both routes are city-operated under the MTA Bus Company brand of MTA Regional Bus Operations, and are the only two local routes in the Bronx to operate under the MTA Bus brand, rather than under the MaBSOTA brand that all other Bronx bus routes operate under.

The Q20A and Q20B and Q44 bus routes constitute the Main Street Line, a public transit line in Queens, New York City, running primarily along Main Street between two major bus-subway hubs in the neighborhoods of Jamaica and Flushing. The Q20A/B terminates in College Point at the north end of Queens. The Q44 continues north into the borough of the Bronx, terminating in the West Farms neighborhood near the Bronx Zoo. The Q44 is one of two Queens bus routes to operate between the two boroughs.