[2][10] The line had previously continued over the Williamsburg Bridge between 1904 and 1923 and during the 1930s, using the southernmost trolley tracks, to the Essex Street terminal in the Lower East Side of Manhattan.

The B46 SBS operates between DeKalb Avenue and Kings Plaza only, while the B46 local continues to Williamsburg, making all stops along Broadway.

The B46 SBS does not operate during early morning and late night hours; during this time, the B46 local covers the entire route between Williamsburg and Kings Plaza.

The route runs through several high-crime neighborhoods, including Flatlands, East Flatbush, Crown Heights, and Bedford–Stuyvesant.

[27][31][33][34] At the time, the town of Flatlands was largely rural farms, and most passengers on the shuttle line were beachgoers.

[13][35] On February 15, 1931, Reid Avenue cars once again began running to Manhattan after municipal shuttle service ended.

[43][44] In the 1980s during summer months, the B46 as well as the B9 were extended south of Kings Plaza across the Marine Parkway–Gil Hodges Memorial Bridge to the Rockaway peninsula in Queens to serve Jacob Riis Park, with a federal subsidy funding the extension.

An aggressive marketing program and the implementation of limited-stop service on the B46 were put into place to better compete with the vans.

[11][19][52] The incident led to the strict enforcement of the Metropolitan Transportation Authority (MTA) policy not to confront fare evaders,[11][19][20] and installation of Plexiglas partitions on many city buses to protect bus operators; previously drivers were only protected by a single metal bar.

[53][54][55] The same year as Thomas's stabbing, the MTA and New York City Police Department (NYPD) began deploying teams of police officers as well as squads of uniformed and plainclothes transit security officials (called EAGLE teams) on the B46 and other target routes to crack down on fare evaders, in the spirit of the broken windows theory.

[57][58][59] The B46 was identified due to high ridership, isolation from subway service, and slow travel speeds caused by traffic congestion.

The B46 Local would cover the Broadway portion of the route at all times, due to lower ridership on this section of the line.

[1][4][17] In May 2015, the MTA and the New York City Department of Transportation (DOT) announced plans to implement the B46 SBS in the fall of that year.

In late 2019, the MTA indicated that it would start using articulated buses on the route by January 2020 to increase passenger capacity.

[65][66] As part of the redesign, B46 local service north of Woodhull Hospital would be discontinued, and closely spaced stops would be eliminated.

[67] The B46 SBS's morning rush hour frequencies would be slightly increased, but the route would remain otherwise unchanged.